That's one of the old EZ P-51s. Great flyer. The covering is backed with foam. DON'T use regular CA on it - it'll eat the foam. Some oderless will work with it, some won't. Bob Smith's works, Balsa USA's eats it up.

If you're only trying to seal the gaps, I'd use clear packing tape. Clean the area first, then tape over the leading edge.