Hi Rowan! I think your question would best be answered at the Lamp Guild Q&A, linked at the top of the bulletin list. This looks like an old nautical multi-purpose lamp that could be used as a navigation lamp but was used in a cargo hold, judging by that nasty looking cargo hook. It's brass and appears to have a whale oil burner, but I would be suspicious of any lamp that has rivets in its construction - usually a sure sign of a replica. Be sure you look closely, inside and out, for any identifying markings. Good Luck!