Faucet Stem replacement help

[whiteb01]

First time here and hoping to be able to mine your knowledge to help me out. I need to replace two faucet stems. Long story short, a previous owner converted a shower into a vanity and mounted a mirror over the shower knobs. Before they did that, they cut the stems off and covered them with the mirror. I want to turn the vanity back into the walk in shower that it was supposed to be. Shower walls are tile with L&P behind that so I don't really want to tear that up to replace the fixture. The bathtub has what appears to be the same fixture (behind tile and L&P also) but the stems will interchange so I am confident it is the same brand. Anyway, I am attaching a picture with some key measurements hoping someone can point me in the right direction. I keep coming up short on the Danco site. House was built in 1938 if that even matters.

Thanks in advance and I've had fun looking through this site. I'm sure I'll be back.