So I have detail stripped my 1911 twice without too much issue other than putting the hammer pin back in. It doesn't appear that this should be too difficult and everything appears to line up, but I'll be darned if I don't have a hell of a time with it. Any tips? Pushing the hammer one way or front or back?
Are you trying to put the hammer back in with the main spring housing installed? If so do not push the MSH all the way up, just push it up far enough for the hammer strut to sit inside the main spring cap.
Ah, so maybe that's my issue. Yes I am trying to put hammer in after mainspring housing has been pinned back in.
Well, that right there is your problem! Seriously, the whole gun should be re-assembled, including the guts and grip safety, before finally pinning the MSH in place as the last step. You do need to start the MSH on partway to hold the sear spring in place though after you get past the sear & disconnecter & pin.