Jack,
My suggestion would be to check out the "n-ssa.org".
They shoot a lot of Spencer as well as Henry. (Spencer in 56-56, 56-52, and 56-50 along with Henry in 44-40 and 45 Colt.)
Also look in their vender section for "Moose Moulds". These folks offer probably the best variety of moulds for these calibers.
For my money, I like the heavier bullet offered in the Spencer calibers.
I hope you find this info helpful.
My best,
Blair