You will have to provide your own catch. I am away from my suburbans and I can't confirm that they both have provisions. The most you would have to do would be to drill holes for the mounting screws and at the worse, make a slight modification to the sheet metal to allow for a flush fit.
If you are using a clamshell lower piece and installing barn doors, you will have to weld some sheet metal to close off the hinge locations.
The hardest part you will find will be removing the complete piece. You will have to cut some welds, remove several awkward bolts and spend a lot of time in the removal process. Be careful in saving the metal strip that separates the linoleum from the rear step. The bolts that hold the metal strip are also difficult to find, so be careful when you are removing these too.
