Clyde Moore at D&D Gunsmiths in Troy, Michigan built one for me back in 2002. I don't know if he still works for that shop, but I'm quite happy with my rifle. He built himself a nice one in .450 Nitro, and I really liked it, so I found a .375 H&H and he rebarrelled it to .500 Nitro 3 1/4" and built a nice quarter rib machined for Talley rings. He had to open up the loading slot a bit to fit the big case. The rifle functions perfectly and shoots great.

SSK Industries also does a lot of No1 customization.

Cheers,
Rick