skinny seals

For the 904 transmission, there are two different gasket and seal kits. The early one fits from 1960 to 1971, and the later one fits 1972 - on. I don't know specifically what the difference in the kit might be, and because I retired from the parts industry a number of years ago I don't have access to kits to look at and see what the difference might be. Unfortunately the individual seals, even when I worked were not available as separate pieces, but only in a gasket kit. You might want to check with a local transmission shop and see if they have some of those lip seals loose. If that doesn't work for you, check and see if you have a Transtar, or W.I.T. outlet near you and order a complete gasket and seal kit from them. Of course, you'll have to tell them the year of the transmission to make sure you don't repeat the problem you've got already.
Hope this helps.