Don't be too sure about the tin. I grew up in Idaho Falls, not too, too far from Cour de'laine. They salt the roads in winter, the fools. Eats up steel quick. Your best bet is to find something which has been sitting in a field or barn for 30 years.

Your winters must be very harsh indeed to say that Idaho winters are milder. I've never thought of -20 degrees as mild!