1911 fitting is a whole lot of filing and tinkering. A LOT of filing and tinkering. It takes a lot of measure 5 times cut once, and 1911s arent designed to fall together; they just don’t work right unless everything locks up perfectly.
You’re going to need a good set of small diamond files, a good whetstone and oil, a way to precisely align the whetstone to a linear guide for sear/rail adjustments. You’re also going to be using a lot of dykem or similar layout fluid. I strongly recommend digging up a set of 1911 blueprints and calipers, and cross-referencing several guides on 1911 gunsmithing. There are nuggets of gold and nuggets of shit in all of them.
I’d say the Stealth Arms kits and jigs are the best available right now, but a little birdie told me that might change substantially in the next 6 months or so...