Surgery set case with military sliding latches and a keyed lock Single sliding latch case The presence of a keyed lock and sliding latches or a single latch on larger cases is highly unusual, so these cases shown below are very unusual and not typical by any means of military sets during the Civil War.  The upper empty case showed up on eBay in 2008 proving the double locked cases did exist and we do see examples of 'real' Civil War surgical sets which are double locked.  One is shown in Edmonson's book too. The lower images of a single latched empty case showed up on eBay in 2010 and is a Hernstein Civil War era military case with an unusual 'USA' marked brass plate, which is more typical of small trepanning cases.  This is the only 'USA' only marked brass plates this collector has seen on a larger military case.