shower cartridge

ok so I got into changing the cartridge on this shower... and snapped off the left shutoff valve screw... My questions for you: 1. any idea on the brand - not visible anywhere. but I included a picture of what could be a brand on the side of one of the taps in the house. 2. any idea on what...

This is an American Standard (All-in-One Temp) Shower Control. Please tell me how to find the product number, and take out the cartridge. All this tenant is getting is cold water from the shower, the temp control no longer works. Thank you in advance for your help and advice.