Here is my entry into this GB, I've already worked on it, but haven't gotten around to posting the build log until now. My scratch-building skills might not be as great as the others who have posted, but here I go anyway!
I used the old MPC Harrier in 1/72 scale:
The cockpit detail is almost non-existent, but I tried my best to replicate a bit more than what the kit provides. The canopy is one piece and a bit thick, so not much is seen through it anyway.
I added two fishing weights in the nose, because I didn't know if this would be a tail sitter, but I decided not to take any chances. The super glue I used ended up fogging the canopy, but I popped it back off and fixed the problem.
detail before scratch-building:
Detail afterwards. I added an instrument panel, side wall bracing, and detail to the ejection seat
I then glued the two fuselage halves together, and added the wings. Both joins required a little bit of putty. I also cut open some of the auxiliary exhaust openings in the intake, but not all. Pictures I've seen on the net showed parked Harriers with only the top 4 open. I also dropped the flaps.
While that was drying, I worked on adding detail to the landing gear: wires, struts, a headlight...
OWL