A few of my sets are missing backs and I know some of yours are too.
So I've started archiving pictures of masonite and metal backs with that though that they could be reproduced.
It's just a Flickr set for now:
http://www.flickr.com/photos/7003980...598416/detail/
Some of these I own and can take measurements if requested.
If there's any interest and it grows bigger, I might make a searchable database out of them.
Here are a couple outfits that already make repro backs for radios and TVs. No affiliation.
http://www.retro-tronics.com/ (only radios i think)
http://www.amptechsystems.com/reproductions.htm (630TS, 721TS, etc)
Any thoughts?