Being a woodworker myself and well conected to my local sawmills, if I were to choose to replace my still original but beat-up bed I would look for tight-grained pine (of whatever sort was available) from the very lowest section of the tree trunk. That part of the log nearest the root is saturated with resin and has traditionally been used for windows and door frames, or any part of construction that may be exposed to moisture. It has better natural moisture protection than pressure-treated lumber. I suspect that commercial sawmills discard that part of the tree since it does not cover well with paint (because nothing will soak into it).
I would be very interested to hear if any stovebolters have gone this route. Strictly speaking it is not original, neither will it be as elegant as a hardwood bed covered with a modern finish. But it might outlast
Karl
