Richard : Glad you decided to re-visit this. When you first brought this up, I was going to respond referencing my OSI's (Jeff's "Y" must have been a typo), but I apparently got side tracked.
Before addressing the OSI Catalogs, I have a few observations / comments. Four or five years ago, John (67gta289) contacted me about an NOS set of trim rings that he had picked up, that had a "Part Number" on them that he couldn't find in any of his literature.
The "Part Number" was printed on a paper sticker on each trim ring as C7OA-1210-A. It didn't take long (with the help of the 1960-68 MPC) to conclude that the numbers on the stickers were not Part Numbers, but Engineering Numbers. This conclusion was prompted by the listing for the 1968 Trim Ring (copy attached) which for the 1968 Trim Ring notes that the Part Number is C8ZZ-1210-B, and it is "marked" C8OV-1210-B. One could then accordingly apply this reasoning that the 1967 Trim Ring would be "marked" C7OA-1210-A, and the 1966 Trim Ring "marked" C6OA-1210-A.
Also note in this listing, that for the 1966 (C6ZZ-1210-A) and 1967 (C7ZZ-1210-A) Trim Rings, there is no listing as to their height/ width ; only their OD and ID. Possibly Ford felt that the OD and ID were the "important" dimensions, and the height/ width could "fall where it may", thus accounting for suppliers furnishing the Service Parts in a 2" instead of 2-1/4" height/ width ??
Of course this then also leads to the thought that the Assembly Line Trim Rings were all 2-1/4" and the Service Parts all 2". It would be interesting to compare known Factory Trim Rings with known Service Part Trim Rings to see if this might have been the case.
Now, on to the Ford OSI Catalogs (example pages attached). For those who are not familiar with the OSI Catalogs, these books were published by Ford at least once a year, and many times two or three times a year, to list parts that had been "Obsoleted", "Superceded" by another part, or could be "Interchanged" with another part. These were designated respectively in the book as "NR" (not replaced), "R/B" (replaced by"), and "MW" (mix with). Each catalog covered a range of years (for example, Volume 4 covers 1967-1980, Volume 3 covers 1960-1967, Volume 2 covers 1955-1960 and Volume 1 covers before 1955). Thus a "Volume" would encompass several individual years. I have individual years of these from 1955, 1957. 1961 through 1972, 1974, 1976, 1979, 1981, 1987, and 1990. From what I have observed, these were issued once a year until 1962 (although I have yet to come across a 1956, 1958, 1959 or 1960 one), when they began being issued at least twice a year, most frequently in July and January. Some years, I have found them also issued in November, apparently depending on how many changes were made during a time period. An interesting thing about these OSI's is that they were not "single-year wonders". In other words, if a part were deemed "NR" in 1973, it would still show as "NR" in the 1979 OSI. Likewise, if say a C7ZZ part was "R/B" a C9AZ part in 1970, it would continue to be shown as such until it was either "R/B another Part Number (in which case all would still be shown), or was designated as "NR". What makes this "tough", is to know when the change actually occurred. For example, in my case, where I don't have a 1973 OSI Catalog, if a Part Number were shown as being "NR" in my 1974 OSI, but nit shown as such in my 1972 OSI, the best I could say would be that "sometime" between 1972 and 1974 that part was deemed "Obsolete". To add to the confusion is the condition that appears to exist that parts designated as "NR" seem to be "purged" from the system when a new Volume is released. Thus, not finding a Part Number prior to January 1967 noted as "NR" in any of the Volume 4 OSI's does not indicate that it is still available as it could have been designated as "NR" in a Volume 3 OSI.
Now that all still reading this know all you ever wanted to know about OSI Catalogs (and probably more than you wanted to know), let's take a look at the "Topic Part" in question ; the C7ZZ-1210-A.
I have looked in all of my OSI catalogs from 1966 through 1990 ( a total of 14 catalogs), and not only does the C7ZZ-1210-A not show as having been "Replaced By" another part or even a different Part Number (such as a change in suffix), but it also never appears as "NR" (interestingly, the same can be said for the C6ZZ-12410-A Trim Ring). Unfortunately, I have seen this occur with other parts, so no help there. That only leaves the option of checking the yearly Ford Price Books, yet the latest one I have is dated November, 1966. So, once again, no help. Possibly someone has some later price books in which this could be checked.
Bob
