Here is OEM arrangement - I definitely don't get what the PO did...Attachment 14176

Thanks for the photo that helps

I have a 73 and a 74 I/O single engine covers, and both boxes measure 38.75" outside .not cut, with nice OEM finished edges.not sure what else to say.

Thank you for the info fas, maybe the guy before me installed it in the wrong place will remove hinges ,and slide back 1.50'' is not much ,but they went thru a lot of trouble to scab that piece of fiberglass on

I wonder if the screws for the hinges pulled out of the deck in the original location - if the core rotted there isn't much glass to hold 'em and maybe the PO just moved it forward til he found good wood. Mine was rotted all around that area.

You guys were right. It was just mounted in the wrong place. Took off that fiberglass flange he made and moved it back into position. Now I'm water tight.