[cadillac_al]

I have contemplated that repair in the past and I always assumed my local sheet metal shop could make me some of those support ribs for a reasonable cost. I think your butt welding will be strong enough. There will be no pressure pulling them apart, only downward pressure forcing them together.

There is another post here of some good beds in PA. I would drive from MD to PA for a good bed. You may even find some closer to you.