Oop old thread. I've been very busy with work.Welcome! Glad to hear I am not the only one overwhelmed but then again your ahead of me on this hobby I'm still at ground level not even a supergun yet. You mentioned bootleg first I have seen that term used what exactly qualifies as boot leg?
The bootleg I was considering was Cadillacs and Dinosaurs (the beat'em up not the one by Elon for the Sega CD). I've only seen one CPS1 board for sale once or twice from years ago. All I ever see now is bootlegs. I can tell their bootlegs because the connector is one long strip instead of having that notch in it and also that CPS1 is encompassed in a plastic shell similar to the CSP2.
I hope you've found your footing with collecting, it's difficult to not just keep running full force XD. So many arcade games.