I have a line on an 1873 Trapdoor with a very very low serial number of 84X. It was a first year production and looks okay. As far as I can tell the stock is original and had the correct markings. the rest of the rifle matches. The lock is tight and barrel has good lands the blueing is only 10% at best but not a rusted rifle either. It has the sling and bayonet. Any idea if this is a good buy for $900?