Bought a Stainless Para Expert 1911. If I actually get my rebate, should come out to $350. Here's the story:

Slide / frame fit is actually very good. No slop, no rattle, no wiggle. Trigger pull was lousy. Series 80 style system. Creep starts at mile marker 1 and breaks at 15. Nice clean break though. I ordered an Ed Brown hammer / sear / disconnect but while I'm waiting I figured what the hell and cleaned up the MIM factory parts. All done on a fine stone, no dremel tools, just to the point of taking off the black off the parts. Did the disconnector flats, cut a relief angle on the sear (left the primary edge by the factory alone) and hit the hammer hooks with a few strokes on the top (hooks are now same height as the total thickness of the sear edge since I'm figuring this is why it had some much creep. I did not touch the front edge of the hooks or, as mentioned, the primary angle on the sear (and I didn't do anything to affect the overall length of the sear as in re-doing the primary angle). Took the high edges off the series 80 parts on the sides. Polished the back of the trigger bow (but not much as there's still "black" in the middle of the bow.

Put everything back together. Thumb safety (not touched) works fine. Grip safety does not work. does not contact rear of trigger bow - by a good bit at that (more that what I would consider a hammer / punch peen fix). As best I can figure, the grip safety was fit with the loooong original trigger creep in that there was plenty of time for the grip safety to stop the trigger bow before the sear came off the crazy tall hooks (which they are still pretty tall - like I said, I didn't take much off them).  The combination of the slightly shorter hooks and the relief angle on the sear (about 20% of the total edge of the sear) is releasing the hammer before the (short) grip safety tang is stopping the trigger bow. But to tell the truth, I never really examined the grip safety before the project so I don't really know at what point the grip safety stopped the trigger bow from the factory.

I've looked at it backwards and forwards and can't see where I would have anything assembled incorrectly. Is my thinking sound or am I missing someting. The thumb safety still works fine, and the trigger now is about 1000% better. Very little creep, smooth, clean break - it's just that the grip safety doesn't work now. I'm thinking a new grip safety should solve the problem.

Fit a new grip safety for sure.  Take your time.  

Sounds like the original grip safety was improperly fitted to begin with, if it allowed enough trigger movement to even begin pushing the sear off the hammer.

^ This

Yeah it sounds like the original grip safety was monkeyed with (to maybe disengage sooner with less grip strength?) or even replaced with a poorly fitted replacement.

Kind of what I'm thinking. I think gun had such a long trigger stroke, the grip safety with an "average" length tang never let the trigger bow move enough so the fastest fix was to just keep filing on the grip safety tang (and It's pretty obvious it's been filed on) to get it short enough for the long trigger pull. It's speculation on my part but I can't figure out why the grip safety won't engage once the trigger pull was reduced.

Sear spring finger not resting on correct spot.

Problem solved with an Ed Brown replacement grip safety. Didn't even have to do any fitting although the backstrap profile doesn't quite match up pistol to new grip safety. If I get brave I might blend it in a little bit later.