Would a Wurlitzer tenor sax neck, serial number 145,160, work. It looks like an early Handcraft. The neck does not have a brace.
I may be mistaken, but I seem to remember that most Martins have a longer body and a shorter neck compared to other brands. I have masured my alto (Handcraft from 1929) recently and this holds, my tenor is a different model so I am not sure. Maybe a Handcraft tenor sold for parts on ebay could be the solution.