RE: U-Can-Do 60 with OS 91FX and other suggestions
I can only answer some.Use tape to seal the edges,its easy,like scotchtape for Xmas presents..
Most engines dont fit the cowl well,dont worry about the 91,its probably a good choice for this one.
Sullivan wheel is OK but not the best,better than stock by far.
Good choice to wait on spinner until you find the perfect prop.