The balk ring is also called a blocker ring in some manuals. Basically, it prevents the overdrive solenoid pawl from locking the sun gear control plate until everything is syncronized up properly.
I have managed to ID the trans, it's an SM318. I was loking in a Chilton manual at the linkages, and see why yours look like it does. There's a lever that's frame mounted for 2nd and 3rd that uses a cross shaft to connect to the lever onthe trans. It fits over the pin on the trans shaft, and a cotter pin locks it on through the hole on the pin. The hole on the other end of the trans lever is for an alighnment tab on the cross shaft.
BTW, I've got parts 1 and 2 shot, not downloaded yet. Part 3 is being a bit of a hassle due to the poor condition of the trans I'm using. it's an SM318 out of a '57 Bel Air convertible, and was used behind a 283 Power Pak dual 4 bbl. Needless to say, it had a very rough life.
