Shower faucet cartridge identification

[eharrach]

Hi,

I am unable to identify the manufacturer of the shower faucets in two of the bathrooms in my house. My house was built in 1964 and I assume that these are the original bath/shower faucets.

The cartridge has the following written on it:

US Pat 2923315
708 M.F.

I have two of these tub/shower faucets, both are in need of cartridge replacement. The shower is in immediate need of cartridge replacement or I will need to tear up the shower to replace the faucet. I have attached two pictures of the cartridge, can anyone identify the brand?