Help identifying lens board (C-1?)

[Scyg]

I recently picked up a lens on a cast aluminum lens board that was badly surface corroded, but otherwise perfectly good. I'm leaning towards it being from a Calumet C-1. Can anyone confirm this? Also, on some sites these are referred to as C-1 / Deardorff lens boards - are they interchangeable?
The third photo shows markings on the interior side - C1-10-8C.
Any suggestions would be appreciated.