:The Beitman index suggests that you use RE-278 schematic which had the same chassis shared with the 440T circa 1950. Four tubes?. Here's that link on this site for comparison. The case would be different cosmetic wise but the chassis would be the same.
That link:
http://www.nostalgiaair.org/Resources/230/M0001230.htm
Hopefully it's a match
Best
Ken