To answer the original question, I'd use 15n20 and 108X (1080, 1085, etc). Stack up about 12 layers, forge weld them together, and then twist the billet several times. For higher layer counts, prior to twisting, you could cut the billet into equal lengths, stack them up, forge weld together, and then draw out and twist...
To make the grips, use the existing grips as a pattern, and then get busy with the grinder, files, sand paper, and drill...