Of the various .45 ACP pre lock revolvers are all of them suitable for mounting a JPoint or Fastfire without modifying the gun?

I would like to pick up a 1988 if possible, or a 1989 but want to make sure that I can use the JP enterprises or Allchin mount with no modifications.

Thanks

They'll work as long as they are factory drilled-n-tapped in the standard pattern. I have no idea when the factory started doing this though.

All model of 1988s are dash 2s and not factory drilled & tapped. Model of 1989s originally were not drilled & tapped. 625-4s are drilled & taped. I'm not sure about 625-3s.
To know if a smith is drilled & tapped just look for the new style rear sight leaf that is rounded on its front end or look underneath the top strap for the three threaded holes.

That's what I needed to know, thanks.