I wish I had something like that, but I never got into PowerPC Macs, I bought into the ecosystem with I think the second generation of plastic Intel Macbooks (which, looking back, were quite terrible), and while there's still an early 90s Schneider home computer somewhere in the basement, I fear it won't work anymore and not be any joy to use anyway; that thing was incredibly primitive. It took almost a whole afternoon for my dad to make it play a really simple child's tune for little me. I don't think I appreciated it properly at the time.

I wonder if a Pi 4 would have the horsepower to run a PowerPC emulator with OS 9 properly. If it did, the biggest difficulty might be finding a decent small-ish external screen.