I had never heard of a Rheem Richmond toilet until now. Perhaps some of the old pros have seen them. I did a quick Google search and it appears they were around in the 50s and 60s. Rheem and Richmond are now in the water heater business. The Rheem/GE is a popular brand, Richmond I think is or was an economy heater. Pretty sure there are none sold now, and they are so old I doubt if repair parts are available. They wouldn't be worth fixing any way as they would likely be 5 gallon or more per flush units. I hope you're just curious about them and not trying to patch one together.