Steve Hughes' book "Custom Rifles in Black and White" has some pictures of custom guns made in the truest British fashion. Mark Silver's .404 pictured in the book is the truest British styled rifle I have seen made in modern times. as It also has excellent pics of other styles of custom rifles as well and I heartily reccomend you pick it up. The great thing about the book is that a gunmaker was tripping the shutter. There are shots of rifles in there that are not found in any other texts. It would be a great reference for you while working on this project.
I would think that you had already checked out the big English makers, but in case you have not, here are some links to their sites
Holland and Holland Westley RIchards Purdey Sites for used British guns:
Champlin Hallowell
