Re: other letters pictured here
Nice find. The chips are clay composition, not bakelite, which is a plastic. I'd test the market by selling some loose ones on eBay. Depending on those listings, I'd keep a set of 100 or 150 together. I could sell you an old 100-chip wood rack for very little, maybe a 150-chip rack. Maybe keep groups of 20, 20, 20, 15, 15 and 10 = 100; or 30, 30, 30, 20, 20, 20 = 150. Off hand the box you show doesn't seem that old. It would be quite a find if it was as old as the chips. Maybe show it to some antique dealers to assess the age. The top looks nice, but modern.
Robert