you have a gap between the 243 and 30 cal, but you have nothing big,
so get the 45-70 in the BC condition, higher priced sites and all. But, the question is, do you have a straight grip stock. You will not be able to shoot open sites with a monte carlo stock. And, unfortunately, with the cost involved with the BC barrel and sites and perhaps stock, the BC is one gun I think should be bought as an entire gun and not an acc barrel. The BC stock is walnut.