I had my eye on a 41 that had been converted to a tenwheeler .the cab and chassis was there but the rear axles had been stolen. It had a single sleeper with crank out windows I think it was accessed thru side door as opposed to the crawl thru that later came thru. It was in fair condition having been in the barn since the early 50's unfortunately a hurricane came thru and dropped the barn before I found a donor truck for axle. that's the only one I've seen of that vintage with a addon sleeper box. good luck in your hunt.