Outside of the countersink and the Stealth Arms jig, I really didn’t have to buy anything else. My dad was a gunsmith in his younger days, so I had access to all his tools and supplies. Admittedly, I’m only talking drill press, big rubber mallet, lapping compounds, and sandpaper. I already had bastard and needle files and everything else.
The bastard files were from Harbor Freight, and that I can recall, only used on blending of the back of the slide.
Needle files were used throughout for fine fitting. They can be had at most hardware stores.
Countersinks can be found on Amazon, or you can just use a drill bit depending on the angle on the tip of them.
I do have the items that I need to buy itemized.