Here's an idea, have you tried emulation communities? Not just MAME but like deep web forums. Some folks hoard ROMs and boards from obscure games. Legal grey area tho, FYI.
The PlayGamer Vii is a weird piece for any collection, amusing more for its audacity than its playability. If the controller responds half the time, you’re actually in luck – some don't work at all! Might be worth keeping just for the conversation starter factor at parties.
That's unfortunate! Makes me sad to see a good console go to waste like that. I could’ve added it to my non-working collection. Oh well, hope your PS5 stays safe!