In the 'worst ' case, you can use the old lid to make a mold for a new hatch. A fiberglass shop could do that.
If you are not too picky, a hatch could be fabricated using Starbioard. The color probably won't match but that approach would be a lot less expensive than having a mold and a lid made.
The old lid may be repairable. Bring it to a fiberglass shop and see what they think.