How much detail are you looking for?

There are several plans for RC aircraft available, they might be what you need.

Here’s a general view:
http://www.aviation-history.com/travelair/mystery.html

The Beech Heritage Museum has some wings on display:
http://www.beechcraftheritagemuseum.org/collection/mystery_ship.html
The aircraft were designed and built with wings of different spans…making drawings and span numbers rather interesting.

And rather obviously, general aviation historian Edward Phillips has written a very good book on the type…
http://www.amazon.com/Mystery-Ship-Monoplanes-Historic-Aircraft/dp/091113929X/ref=pd_sim_b_1
As you are probably aware, the Travel Air firm was organized by Messrs Beech, Cessna and Stearman and Phillips has written histories of all those firms as well.

The aircraft is also detailed with photos and a basic 3-view in the Beech book published by Putnam.