Is there an echo in here? As I said, collectors probably would pay about new price for it, give or take, and be glad to get it.
It is not just cartridge collectors who would like it. For instance, many gun collectors like to display period-correct ammunition with their guns. I have a small ammunition collection just for that purpose. Remember, the 1950s saw some very scarce collector Colts and other brands. Don't shoot it; sell it.