Quoted from Darcy:
Not sure of this will help.
How ever, an old trick in getting old wood cabinet drawers to slide easier is to rub bar soap on to the parts of the drawer that slide in the cabinet.
Is the channel that the ball release slides in, thoroughly cleaned out? No wood shavings in the way? Has someone blocked the slide by putting a newer nail in the wrong place?
Soap sounds like a good lubricant of sorts, although I don't know if it will help. I don't know that it will change the range of motion moving it forward. It moves freely already, it's not hard to push the coin slide/board forward. Nothing appears to be obstructing or limiting movement.
All parts present appear to most likely be 85 years old. Perhaps the balls have been replaced at some point I guess is a possibility- they are what feels and looks like glass.