Weather was cooperating today, got the box back outside, re-checked everything one more time, then make this pop-out hat!
Figured out what should be slick to frame the opening and the cutout so got that mocked up.
Had hinges on the brain so dug through what I had on hand and rejected every one. The hood hinge on the 620 gave me a great idea to allow it to swing up clear of the box floor. Then I thought, "Hey, you might only need to open this every year or two, WTF - KISS" so a new idea is brewing just bolt it down or some other retainer.
Got too much other life activities happening so won't touch this again for 2-3 weeks