Note: Some of you may have been expecting a different page and have been instead redirected here. There used to be many pages related to my father’s 1965 Oldsmobile Cutlass Convertible, successfully sold in the summer of 2007. Due to space considerations, this sub-site has been removed, except for this page which remains available in case it can help Olds enthusiasts.

Originally Web posted Monday, 25 June 2007.
Content last modified Saturday, 9 January 2021 .
External links last verified Monday, 25 June 2007.

By The Numbers

It took me awhile to begin to get a sense of what the phrase “numbers match(ing)” meant in discussions of these cars. This page is here both to summarize what i have found on the many useful Oldsmobile-related websites i have perused and to show the numbers for this particular car.


I am in debt to a whole fleet of folks who have put up web pages and/or posted in Olds fora. Having viewed so many pages in the last few days and having not kept good records, this list is necessarily incomplete. Here are some of the sites or pages i found most useful:

This Car’s Numbers

Given that this is a one-owner car, the numbers should match. Yet, with years of repairs plus restoration, one cannot count on that. Let’s have a look:

top of the original sales slip with its numbers
The numbers on the original sales order

Comparing with the booklets photo below, we see that the dealer Stock No. has been stamped onto both the Owner Protection Plan and the Convertible Top booklets. Note how the date of sale appears to be the 21st., yet the Protect-O-Plate and the Owner Protection Plan booklet both show the 23rd. Also, the Stock No. looks like 7y66, yet looking at the numbers stamped on two of the booklets, 7266 is much more likely.

Owner Protection Plan booklet, Protect-O-Plate page
Protect-O-Plate page of Owner Protection Plan booklet

Notice how the Delivery Date and Selling Dealer Code Number, typed separately into the booklet, match those parts of the Protect-O-Plate (closeup below) itself. The address information has been fuzzed out for privacy reasons. I have no information regarding the meaning of the 9233 number… definitely not my father’s writing.

Engine number T585813G and Transmission number 66 MA 101 Protect-O-Plate, annotated
Protect-O-Plate, flipped around and annotated in Photoshop

Here i have flipped the normally reversed type on the Protect-O-Plates so that we may read them directly. As noted in the booklet text in the photo above this one, there are actually two plates:

Starting with the pasted-in owner plate, we note that the selling dealer code matches that typed into the preceding page of the booklet. The interesting symbol following the numeral 6 has been identified on non-Olds sites (yes, the symbol there differs) as a brand mark. The following line has the date of delivery, which again matches what is typed into the Owner Protection Plan booklet. The bottom line on the right has the end of the VIN, with the plant code (Z=Fremont, California) and the serial number. My guess is that this information is there to verify whether this pasted-in plate matches the car description plate, and maybe for tracking this plate with the correct car, owner, and dealer through the creation and mailing process.

Moving to the very interesting and informative car information Protect-O-Plate, the first number in the upper-left is the engine ID number as stamped on the engine. It is easy to see that the Protect-O-Plate number exactly matches the number stamped on the engine. The Engine Code Numbers Decoded page points out that the T represents a 330 cu. in. V8 and the G represents High Compression (10.25:1). I was never able to find the two-letter code on the oil filler tube. As it is known that the engine is a 330 with a 4-bbl carburetor, high-compression, automatic transmission, and no air conditioning, the code should be QN.

The Protect-O-Plate code directly beneath is the transmission number… we see that those numbers do not match. There is a straightforward explanation for the lack of match: the transmission case was replaced by Jay’s Automatic Transmission Specialists on 20 August 1976. They apparently used a 1966 case. For those who are interested, other sites note that the 66 (in this case) is the last two digits of the model year (1966 for this replacement case), MA is the transmission model code, and 101 is a production sequence number. The original case would have been marked 65 MK 120, per the Protect-O-Plate.

Continuing in the left column going downward, D1953 is a concatenation of information which also shows up on the Fisher body tag:

The bottom line in the left column contains three accessory codes. What i find interesting is that there are many more than three accessories listed on the sales order, all or nearly all of which have RPO codes. Further, there are two codes which appear on the Fisher body tag, neither of which show up here. My best guess is that the three items listed (N40 power steering, J50 power brakes, U63 “deluxe” radio) are more customer-significant and/or price-significant options than many of the others.

Looking at the right column of this same Protect-O-Plate, the first line is the full VIN, which naturally matches the VIN plate on the driver’s door pillar (photo forthcoming). The breakdown of the VIN is accurately discussed on several sites listed above. Quick summary:

Next line, right column: BF= Fremont, California plant code as listed on the Fisher body tag (Body Fremont?). 596 is the production sequence number on the same Fisher body tag.

Bottom line, right column: the single letter Y. This was messing me up for quite awhile, looking like some accessory code. Nope… notice that there is no month of production information, so far, on this Protect-O-Plate. That is exactly what that Y is. Y= February was the month of production of this vehicle. Because i have not seen this substantiated elsewhere on Olds sites, i now present my evidence.

If one looks at the 1965 Chevelle Protect-O-Plates page and writes down the date information there, the following pattern emerges:

Now we will leverage off this Chevelle information. Fill in the gaps and one sees that the year starts with Z and counts alphabetically backwards. I hesitate to speculate later in the year than August, since we go from T in June to W in April, which leaves both U and V for May (and i do not know which was used). There may be other “skippages” in the sequence as it works through to December.

As is about to be discussed below, the clearly documented Fisher body tag date code for this one-owner vehicle is the 3rd. week of February. And, the VIN-matching Protect-O-Plate shows the lone letter Y. And Y would match the sequence deduced from the Chevelle data. I feel confident that this position of a 1965 Oldsmoblie Protect-O-Plate represents the month of vehicle manufacture. I welcome others’ thoughts and contributions here or on any Olds forum.

Body Tag, annotated
Body Tag, a.k.a. Cowl Tag annotated in Photoshop

Plenty of information on this typical Fremont, California Fisher body tag! And, fortunately, well documented by others (other than my thoughts on the second trim number). I’m mostly going to let the photo annotations do the talking. We see the 2C date code, indicating production of the body during the 3rd. week of February.

As far as the second TRim number(13)’s meaning, here is my evidence and my thoughts:

I have not even read any theories regarding possible meanings of the diamond cutout in the upper-right corner of these Fisher body tags.

Booklets with stamped number
Dealer stock number stamped on Owner Protection Plan and Convertible Top booklets

These numbers match each other and the Albertson Oldsmobile stock number on the Sales Order. No guesses on meaning. Probably used so the items would not get lost while the vehicle was on the lot (which this one was).