I agree with Nun - probably 20's-30's. That is a very nice razor you scored!

One note of caution - I have found that razors on which the "spine wear" isn't actually up on the spine which are ALSO so heavily ground can be challenging to hone. If you end up using tape, you'll probably find that it is the very bottom of the tape that touches the hone. I know of two ways to address this - use something to "build up" the spine OR be very very very careful to always put the tape on exactly the same every time you replace it.