1/72, approximately - Looking at the engines in the plan view, and comparing them to a 1/72 aeroclub Austro-Daimler I had in the stash,
I figured out the ratio to make them match, and printed out the drawings accordingly. Not the most scientific method, but it looks about right.

Should be warm enough tomorrow to stain the interior and maybe build the blower engine. Thankfully, there's only one of those, and it's a
a four cylinder.