I mentioned that the FN Mauser carbine
(the K98 rifle/carbine clone; not the pistol) rear sight will fit the Broomhandle; here's a comparison pic of the 50-1000 sight and the FN carbine sight...The leaf, slider, and flat spring will all fit the Broomhandle
(some minor hand fitting may be required)...
1400 meter Broomhandle...

Well, it's no more optimistic than an Artillery Luger...
I've fitted one of these to my long-barreled C96 wildcat; I'm sure others have done the same...Original C96 50-1000 sights are difficult to find, for some reason...