I found an old upright with a sound I like but the action is old and crappy. Can I transfer the action from another (different) upright into this piano?
Almost every piano maker uses their own design for the cast iron frame that resists the string tension, and the specific positioning of the strings.
If the two piano cases have different heights (measured from the ground) then the vertical height of the hammers above the keys will probably be different as well.
Therefore, the chances that you can successfully move an action from one model of piano to another are very small, because the hammers won't line up with the strings.