@ Sig999
One thing I do know is that you won't be able to plug the 3.1 ROM straight in with that board revision. You'll need to solder or clip a lead joining pins 1 and 31 of the new chip. It's an official workaround to bypass an addressing issue with the newer/larger ROMs and the older boards. Again, precise details on Aminet.
EDIT: Actually, hang on, I'll need to check that board revision issue.
EDIT2: Nevermind, it's only 3.x motherboards that need that jumper. Feel free to ignore all of the above :-)