It might be interesting to confirm what version of Cavalry boot or scabbard was being issued between 1892 and the Spanish American War.  The trapdoor carbine had, I think, a similar problem with the Buffington sight and the 1887 Boot was designed with a brass reinforcement at the opening to protect - what?.  The sight or the boot?  Was the boot still planned to be used for the Krag?  Maybe the thinking was that it would be cheaper to redesign the sight to work with the latest scabbard.  Instead of a rework of the 1892 sight, it was thought to totally remake the sight.  When was the 1896 sight available?  Wasn't it issued on the carbines with the 1895 dates?  Between BR's Smithsonian-like computer and Mr. Hosmer's experience we can find all we need.