I bought 16 gauge black iron sheet and made my own.
I replaced 3 floors (should have been all 4) and gas welded them in.
Since I had started to wear bifocals since I had last done any gas welding,
I spent about 5 weekends in the Albrook AFB auto craft shop welding them in. I've got some magnifying welding goggles since then and they make things a lot quicker.