RE: Westland Lysander
The canopy and greenhouse on a Lysander would not be pulled from a plug, it would (or should, IMHO) be built-up much the same way the greenhouse is best done on a Piper L-4.
The polycarbonate window material can be ordered online for chump change.
EDIT : If you manage to come up with a set of plans, there's a version of the Lysander I've always thought interesting . . . photo 4. The beast was a model P-12 and was loaded with guns for strafing beaches, when the Brits thought the Nazis might try to invade. If nothing else, figuring out the CG should be "fun".