Dehler DB1 Leak

[Wielingen]

Hi All!
I'm currently helping a friend to restore his Dehler DB1. We've run into a problem with the under cockpit storage area. The yacht is currently parked on the yard. Last week during a thunder storm water gushed into the under cockpit storage area through the cockpit trapdoor (don't know if that is the right terminology - I can't find the term Dehler use themselves). Moreover, the trapdoor is stuck (we suspect the door was glued shut by the previous owner), so we don't seem to be able to figure out the cause at this stage. We may have to break the door out before we can tend to the problem...
Here are our questions:
1/ Does anyone have experience with water coming in through the cockpit trapdoor in a Dehler DB1? If so, what was the cause and how did you solve it?
2/ In case we have to break out the trapdoor: What would you suggest we replace it with?
If you have any photos of your solutions, we would be happy for you to share so we can take a look at them and get inspired :-).
Thanks again for your valued replies!

[psk125]

Is this the boat? https://sailboatdata.com/sailboat/db-1

It would seem to have a cockpit seat locker that could leak into the space under the cockpit. If it's been glued shut and still leaks, it definitely needs fixing! If it has been glued you may have to cut it open if it won't pry apart gently. In that case it might be best to avoid cutting the lid part, since that will be hard to repair without it being an obvious repair. If you have to cut, cutting into the seat close to the lid, but not the lid, may enable you to hide the repair beneath the lid once you are done. YOUR photo of the problem area might be helpful here.

[Wielingen]

Thanks, PSK125! I'll upload a photo asap.

[Wielingen]

Yes, that's the one!