Hi Bill. Looks like I'll be the first to post in this thread too
There were two 10" bakelite models from Admiral. The 20X122 is from 1948. the very similar looking 24A12 is from 1949.
The 20X122 has a single chassis with a brass colored bezel. The 24A12 has a split chassis (lower half has the power supply and audio amp) with a white bezel. Here's what it looks like:
http://www.flickr.com/photos/jeffjackson/4009712023/
Sounds like your set is really missing a lot of stuff. Even the speaker is gone?
I hope you can find the right replacement because the field coil doubles as a filter choke for the B++ supply.
Good luck
Bob