Find a route operator and walk into their shop. They may have a stack of them. The operator I worked for removed them as both chutes were for quarters so we did not need them. They made handy bins for parts in the shop or service tech vehicles. The 3 chute doors had SBA Dollar coin chutes in the middle which went unused. Even if a few strays made it in, The coin counter/wrap machines just let the SBA coins stay in the bowl.

Divots are for "security". If padlocked in place and the door opened by a tech, The padlock was to prevent them from accessing the cash. The divots were meant to prevent pressing on the cach box and flexing it enough to disengage the lid so one could reach in and grab coins.

Older cash boxes by Bally had steel dividers that slid into tracks of the cash box. Lift the dividers just a bit and the dimes mixed with the other coins.

Or three of the small ones for machines with triple coin chutes.

ERROR: See a few posts down.

You are correct. I'm thinking of the Williams cash boxes from that era that had the narrow tray for the center chute.

Note that Williams trays are tapered on the bottom-front as well versus Bally trays that are flat.