Dunno, might be a carbon steel blade, looks like a bit of rust? As for the shackle pins, from the looks of it, you would have to take the knife apart to replace them, since it is not a through pin. If the shackle is loose, you might be able to peen them a little to tighten the shackle up.
Nice score, at any rate. Congrats on a great addition to the collection.