Doug, the time and effort spent getting a panel cover fabricated will not likly be recovered in the job. In my opinion it would be an un-needed expense. Screw the cover shut and be done with it.
I agree this isn't the kind of thing you would have made special but if you could come up with a part number of a cover that would work it would be worth doing. How many cabinet sizes are there? Nobody said it had to be a perfect fit. You might have to drill a couple holes