Definitely plus one for Rigbymauser's opinions. Especially in the US, full refurbishment, barrel, woodwork and re case hardening is very popular and acceptable

The top names, Purdey (rare and very expensive in rifles) and H&H, with Alexander Henry are probably the tops, but all the better names are equally good, although almost all makers bought in from the Birmingham trade, especially from W&C Scott

.450 / 3 1/4" is a very good calibre (one of my A-H falling blocks is in this), but the .500 BPE (mine a George Gibbs S/S) is good, more versatile, originally more popular in India, and many have come back from there over the years, and probably best value for money

You will pay more for a .577 in 2 3/4", 3", & 3 1/4"

On re reading your post, take these opinions as more relevant to my own favourites, the hammer rifles of 1870-1900

Be aware it is very easy to get addicted to these wonderful rifles

TH44