First off, that is beautiful work of the highest class! Superbly executed. The steel you want, to be really correct, would be shear steel, or cast steel. In modern steels, 1070, 1080, would be close in carbon content and simplicity. As you probably know shear steel is blister steel folded and hammer welded much the same as what we call damascus today. Cast steel is made in a crucible. It would all depend on how far you want to take historical correctness. Shear steel would be somewhat expensive, in time or money, whereas the 10XX steels are cheap in price, and considered by most to be a good substitute for the early steels.