Where have I seen this one in recent memory? The lateral shelf in the back is a giveaway. Only a guess but may be changing hands often. Some funkiness up front with strange mottled coloration and a double row of ?? adjacent to seam. Double hull won't prevent leaks
but will obscure the source. In the plus column no air no furnace
no bath and (possibly) no water heater means less weight
and less to go wrong.