I had a slight gap on one side, 1/32 maybe .It didn't affect it.
As long as the main wing was straight. It didn't bothered me.
I use cable ties to keep the wing halves in place.

What caught my attention more was trying to get the
main wing and the tail horizantal stab parallel to each other.

There wasn't much I could do with the main wing aluminum tube.
Usually you could fix this problem later, just sand the main
wing saddle's, on other types of air ships.

I sanded the stab's saddle as much as I could. To try to get it level.
The stab's wires will help if it's off, but it's not easy.

I made sure the stab and wing would be able to get parallel as
much as possiable before I glued the stabs.
Close one eye, so that you don't get fooled and stand back
It's easier to tell on the SE becuase of no diehedrail