Look at the plans. It's basically a Stick. OK, there are some differences, buy I could easily make one from an ARF Stick kit.

A Stick has a flat bottom with the stab on the bottom. The RCM Trainer 40 has a flat top except for the fake, built-up cabin and has the stab on top.

Flip a Stick fuselage over, fill in the old wing saddle & cover, built a new wing saddle/cabin on top, change the shape of the horizontal and vertical tails (make new ones out of 1/4" sheet, if you like) and move the fin slightly forward.

You'll also need to add a new main gear mount and maybe some cheek cowls.

Looks to me like that's it.