VeeAte

Sticking bits of balsa on the cracks in the ribs is fine, may not look nice through transparent film but you can get over that with solid film as you are recovering to whole wing anyway.

Flat spun into the ground now thats interesting as my version comes out of spins immediatly, I wonder where that chap had the c of g?

As too measurements the best way is to establish the engine thrust washer position in front of the wing LE attach the spinner you will use and just infill between the two to your own liking, don't bother trying to exact copy the originall its not neccesary, just as long as the thrust lines and distances are the same. I would probably establish the spinner position and thrust line stick the spinner on a long piece of balsa and stick it somehow to the fusalarge in the correct line and position, next mark on the stick the position of the firewall for the engine mount, mark out the engine mount on a piece of 1/4" ply and cut out at approx width that was in proportion to the existing width and spinner dia, same with the height. Next two pieces of 1/16"ply long enough to go from inside the fus at an undamaged postion all the way to the spinner width to suite the fus depth, epoxy them to the inside of the fus on both sides and attach to a 1/2" balsa spinner ring ply faced on the front. Epoxy in your firewall and fill in the gaps with balsa you should have the idea from now on. If not ask and I will try to guide you.

Good luck

Mike