You can obviously fabricate anything well. What was your reason for making the cover plate lock in place with two lock pins? Seems like an unusual design choice and not so easy to fabricate, either.
Actually, I saw a new JD tractor,, at a dealer, recently, the battery box had very similar construction.
(AND, in the same location!!)
Two pins, tabs on the door,, I was not gonna reinvent the wheel, because, THAT looked OK to me.
Also, I did not want to deal with hinges,, they rust to an immobile state WAY too soon.
My BIL bought a new Ford pickup in the late 1970's, it had a built in door on the body side.
He put some tools in it the day he bought it.
Within a year, the hinges had rusted solid.
When he decided to sell the truck, he ripped off the door, because he had forgot what was in it.
There was nothing to speak of, typical farmer stuff, adjustable wrenches, and hammers. etc,,