Where is reverse?...

I got under the car today... Here's what I found... The tranny ID pad had the following: PP8336857 and 7B176942 casting 18803 dated 7-23-76... The tail shaft casting was 013386 dated 8-31-76... It also seems to have a couple of leaks, but not to sure from where at this point... So, it seems there's a lot of mixed parts in this car, with the motor being a 340 cast in 5-31-72... Thanks for the great feedback, you guys know your stuff!!!!...