ford-o-matic help. experts please

Here's the story: im working on a 1962 mercury comet with the 2 speed ford o matic (merc o matic). I am 100% certain that i have correctly identified the trans.
When in park on an incline the car is able to roll forward, making a clicking sound. When in park on a flat surface, revving the engine will cause the car to kinda surge forward. Sometimes it will be physically difficult to take the shift lever outta park. I have carefully adjusted the linkage, which was initially a little off, but really no change. I have no information about service history on the trans, its not my car.
My question is: are there some likely causes that i can look at first? I don't have experience with this particular trans but if somebody with some first hand knowledge could provide some insight i could make good use of it. Thanks!

Also, i did a forum search before posting and didnt find info related to these problems

 

Sounds like the linkage is still not right. Remove the linkage, put the lever on the trans itself in park and see if the car still wants to roll at that point. If it does, you have an internal problem, if not, you had the linkage adjusted wrong.

 

Thanks, yea i forgot to mention that i already isolated the linkage and put the trans in park by hand. Pretty sure its an internal problem so i wanted to see if this was a fairly common set of symptoms and what to check first. I plan on dropping the pan tomorrow to get a look at whats going on.