Hi Larry,
I have a plans for the 10V. It's not exactly what I would call a set of drawings. Stuart has crammed all the drawings on a single sheet approx. 11-5/8 x 16-1/2". It's folded in half to make 4 "pages". It includes part drawings for the 10V, 10H, and Double-10, since they all share common parts. It also has drawings and instructions for the reversing gear.
I would be willing to scan it and email you the 4 pages, if you think it would help. A few of the dimensions are quite light and difficult to read on my copy, so the scan won't be any better. I think that once upon a time, Stuart probably supplied decent-size drawing sheets for their engines, but at some point they went cheap.
Send me a PM if interested.
Paula