Like many others, I have a gap between the two parts. The deck is too narrow. I hope I will be able to force them together, when I get to that point.

If you have just recently glassed the hull and deck, my advice is to join the hull and deck together temporarily with tape, as much as possible.
The epoxy will continue to harden for weeks, so the hull and deck will only get stiffer with time.
It seems like a lot of extra work, but now I try to keep the hull and deck 'mated' as much as possible during the building process.