1911-ish progress

So I had me an idea.  One sticky point on my 1911-ish build is that I'm concerned that the mainspring housing pin hole area is pretty thin, and that on a printed lower it will break out and let the mainspring housing go flying.  So then I thought what if I just make the mainspring housing one piece with the grip frame?  That would give me some extra strength in the grip frame, and eliminate the worry about the MSH retainer pin breaking out.  The biggest problem I see with that is that the sear spring has to go on before the MSH, and the MSH keeps the sear spring tab locked in it's slot.  To get around that, I'd add some extra clearance so that I could slide the sear spring in from the top, and once it's tab is in the slot in the mag well, I'd put a pin through the grip frame so that the spring couldn't come out of the slot.  That extra pin would be captured by the grip panels.  Hopefully that makes sense.  Here's a few pics that hopefully will explain it a little better.

Looking from the back of the grip frame, the red pin fills the gap between the sear spring and the now merged MSH/frame, keeping the sear spring in place:

Looking from the front:

Nothing is as good as actually being able to look at the thing, so I fired up the old magic machine and printed some parts.   I printed one with the standard MSH layout, and one with an integrated MSH.  While I was at it, I printed a temporary frame to make sure everything fits together like I want.

The integrated MSH seems to work alright.  It's a bit of a hassle to assemble, but really, once it's together it'll rarely have to come apart.  I put it all together with my slide and barrel, and all the internal parts of the grip frame are assembled.  The yellow printed temp frame isn't really strong enough to hold any spring pressure so all the FCG parts except the trigger and sear spring were left out.  The pin through the grip frame retains the sear spring perfectly.