Hey Thor,
I see that you bought the boat..
She looks good enough.
OK;
As far as the measurements are concerned;
The teak hatch measures 16 3/8" by 42" long.
The hatch has, as you can see rounded edges and is held together underneath with 3 cross members of the same material measuring 2" wide and measuring 12 7/8" long
The two outer ones are specifically positioned @ 1 3/4" from each end of the under panel.
It will be noted that each outer end edges on the two members mentioned above will be rounded off in order to fit the inside edges of the boat's fish well.