Been meaning to ask, do the Joe/TF figures play well with the 25th style figures, or are they specifically O-ring only? I've got a bunch of the former in storage and it'd be a good reason to dig them out.
25th style are of course closer to four inches or above, but just speaking on actual joe vehicles, personal experience, most absolutely fit across the board. If I was home I'd try it out. I bet with knees bent a 25th guy could fit on that cockpit.
I used to keep my o rings and 25th guys in their own displays but I have stopped caring about that and am happier for it.