None of the hardware used is standard. With an exception of four carriage bolts, everything was built from scratch.
The nuts were made from square bar. Each one was cut to length on the band saw, chucked in the lathe and faced square. A hole was then drilled and tapped in each. Each nut was then de-burred and the tops chamfered. All together it took about 2 hrs to make the 10 nuts required.
The carriage bolts were made in two pieces. The head was turned separately and welded to the shaft. Once welded, the square portion was milled. A small jig was made to hold the bolt while milling the square portion.
Each bolt took about 1.5 hours. I probably could have done it faster but I decided to cut the threads in the lathe. A die would have been much faster but I wanted the practice.
Four washers were made from 1/8” flat bar. They were rough cut on the band saw then turned round and chamfered in the lathe. A small mandrel was made to hold them. It took about an hour for the four washers.
The only hardware that was not custom made were the 4 carriage bolts that hold the barrel in place. The only the very end of the threads are visible. It just wasn’t worth the effort to make them from scratch.