Might help as a start to know what type is on your house you're
Try the manufacturers like Georgia-Pacific, Weyerhauser, Masonite (are
they still independent, I don't know any longer?), etc., etc., and see
if you can find it as a product, then find distributor for the
product. Much of the old hardboard has been discontinued, however, so
may not be available.
If larger full-service lumber yards were unable to help, that's
probably a sign, unfortunately.
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