I was just guessing about oil in the day. They had petroleum based oils or trains and steamships wouldn't go too far. I have an original 1849 pocket that still cocks and the steel is strong. Big waggon wheel on the cylinder. I wonder who used it-how he used it and greased it. I can only imagine. Maybe I can tell everyone Doc Holliday sold it to Wild Bill.LOL but the inside of the barrel still sparkles like a new one. It cocks in line but of course there is an excessive gap since the cylynder is loose. I could stone it to where it would fit snug but my better sense says--leave it alone.