I jumped on this unusual box the second I saw it (which photos don't do justice), but am only now trying to puzzle out exactly what it is, and I must say it is a bit of a mystery! From what I can discern, there were two sorts of patch boxes: first, fine boxes, very similar to snuff boxes, some very similar in construction to the this one, made to hold decorative patches for the face, worn by both men and woman in the 18th and early 19th century; and second, boxes made to hold ammunition, sometimes set into the handle of a gun. Almost everything about this one, including the hinged lid (which became common on both patch and snuff boxes in the mid-18th c) suggests the former (and the style of the lettering feels early 19th c. to me); it is just the cross and RIP that make me think it's a trench art patch, or possibly snuff, box. Curious! In any event, quite a wonderful thing I think, perhaps to fill now with pills, or nicotine patches, or anything else warding off the end!
I believe it is silver-plate, as there is brass tone showing through on the face. I have not attempted to polish it though certainly it would polish up some. It is marked England on the interior. 2 1/16" x 2 1/8" x 11/16". In great structural condition, and the hinge operates super smoothly and lid closes flush.