Mar-K has a good article on their website about various bed board finishs and a test of how they stand up to the weather and time. But what do they recommend for an original finish on the boards? I have heard that the factory used linseed oil and lamp black. Although I have little idea what lamp black is and no idea where to get such an item. The only original boards I have seen looked like they were stained black, the grain could still be seen. Would such a finish hold up?