Maybe not a B, as it probably went to the step van builder as a COE cab-chassis or nose-chassis. Not sure though, as Ford could have been building their own step van bodies, or owned a subsidiary to do it, from the pre-war era. 1950's was at the end of the era of Ford's obsession with vertical integration, when Henry II was radically changing the way the company did business after his grandfather's death.
First Ford van that got B-type conversions was the Econoline introduced in 1961 on the Falcon platform. The camper conversions came real early, were usually built on the wagon rather than the van, and were sold through Ford dealers.
This step-van conversion is commercial. The later cab-over is an interesting touch, looks a lot like the one we had on our 1960-built Corsair travel trailer. But if I were buying this for historical value, for a museum collection, I would probably prefer not to have a modification that drastic.
A lot of things about this remind me of that first travel trailer. Boxy cabinetry, metal sink, wall lamps. It is hard to tell whether one of those tall cabinets is a toilet. Ours was in a cabinet that size, right over the single waste tank, gaucho seating to double as sleeping area.
We had a LPG-only fridge rather than ice box, a LPG vented gravity wall furnace, and two LPG mantle lamps, the rest of the lighting 12V borrowing from the battery the tow vehicle. Instead of a hand pump, our fresh water tank was pressurized, with a Schrader valve in the fill cap so that we could use a bicycle pump.