Yes they are the same, I have seen the rings also, But-----
If you look closely at the outside of the syncro "drum" assembly, the brass ring has been staked from the inside of the ring and protrudes slightly into the holes in the outer drum area. This is what holds them in the syncro assembly. This was a factory press operation that would be difficult to duplicate without some specialized tooling. I don't know of any shops in this area that still
rebuild these units. Probably the best you can do is find a good used one.
Other than possibly the bearings, nothing from that 64 transmission can be used in the earlier series.
Fred
