Working with a cat 320 with a manual thumb. to get thumb to stow position, the linkage must come out, and thumb swung parallel to the stick. That thumb probably weighs 500 and I need a safe and controlled way to move it. When setting in a use position, I can control it with the bucket but it is getting to that point that is an issue. In the past, I have used a tree stump or something, but that is not always available.
Sounds like you have the same thumb I have on an ex220,I redid the pins so the linkage stays on the thumb it helped some,
I have a similar thumb on a Cat 311, obviously smaller than a 320 but non the less to heavy to move and dangerous if you arent paying attention. I am able to curl the dipper around and the thumb rolls back into the stowed position. If it doesnt line up you could add some metal shims to line up the holes.