I have exactly the same boat which I purchased new in 2006. We have had problems with the small hatch latches and even had to replace one complete a few years ago when it became distorted after a sheet got caught when in half lock in a F5.
Epoxy resin will stick the old latches to the light but the Lewmar later models have a ‘through bolt’ system which is preferable and avoids failure.
When I went on the Lewmar website to replace the small hatch it was described as a ‘low profile’ hatch and with obvious dimensions.
Sorry I cannot be more helpful; such a shame as we only returned from Corfu yesterday after a month’s cruise and if I had been on board I could have answered all your questions properly.
We will be on board at the end of August so if you still need help, we’ll be there!
Best wishes
Michael Hill