Very nice example, Longknife, you will no doubt enjoy your custody very much!

The British BP .500s are perhaps the epitome of slender elegance vs hitting power: many are described as 'serpentine' whereas a step up to the .577s usually takes us well beyond that paradigm!

Please don't flame me for this observation, but if it is to be taken afield those rear sight-Vs should probably be widened, ...a lot!
Almost looks like they were never filed-in.

Hard decision to take a file to a rifle that has remained virtually untouched for more than a century though.....
(unless the rear sight is a replacement, although it does look original)

If its to be a collector or range-rifle just forget I said anything!