Its usualy not that large. I bet the previous owner sanded the gap larger, so the elevond did not bind.

Heres what I did on my kangaroo, and Eurosport.
I bought some Graupner Hinge tape, designed for high speed gliders. Its thicker than normal tape, and only stick on one half, and it curves slightly.
Perfect for this aplication, so nothing binds, and keeps the gap sealed.