Hello to the camp!
I still have around 200 rnds of 56-46 Spencer brass that is of the later and much more common "improved" shape that due to it's shorter configuration from the earlier military trials 56-46 XL chamber configuration I cannot use.
The improved 56-46 can be used in many, if not most, of the Spencer sporting rifles or at the price I will be willing to let them go at you could cut them back a bit and form them for 56-56.
This lot is made from Starline 50-70 & 56-50 brass.
I'd take .75 cents each and the cost of priority shipping to CONUS.