I've stumbled onto some old square cans of powder, Unique, Alcan AL-5, and Bullseye. The seals haven't been broken and they are in very good condition. They are before my time as a reloader, they are almost a cube with a metal seal on the cap, to open the cap you push in the middle and it pops open, from what I understand anyway. Please let me know if these have any collector's value and how much it would be, they are 1 lb. tins.
Selmer