Another good choice for bed wood would be Alaska Yellow Cedar. It's very rot resistant and weathers well, but you need to use corrosion resistant fasteners, and be sure that the bed steel is sealed with a good epoxy primer. It's generally only available in the Pacific Northwest, so might be tough to come by in Ontario.
No it's not original, but since the bed wood was finished black originally, who's going to know the difference if you use a black finish?
