NOS Player Piano Company, Wichita.  White cardboard pouch lifter discs, 5/8" diameter, about .021" thick.

Available in other diameters in my eBay store.

I'm Howard Gustafson and your success with my products is very important to me.  Please feel free to contact me, before or after the sale, with any questions you have regarding this item.  I've been in the piano business as a technician since 1985 and I'm glad to help.