On my campers I usually cover them over when I reskin. The space isn't practical beyond a few feet. I've seen people create a box a few feet deep on either side then use the middle with storage (not easy to reach) under the bed. One member used the middle area for an AC unit, another member put the bed on a hinge to lift but the mattress must weigh a ton and then there are space issues while shifting it.
Are you looking for a storage box for on the tongue or a hatch door? I would think you can have a hatch door made, if you have one left to use as a template by a machine shop.
Hatch doors came in odd sizes between trailer manufacturers. Sometimes you get lucky in finding a match. The other option is to retrofit a modern door in place. You can see that on this Westerner that was recently completed.
Last Edit: Nov 26, 2020 6:40:06 GMT -8 by Teachndad
"I get that queasy how in the hell will this thing ever go back together feeling.” - PT