What type of English gun? A Purdey sidelock or a Birmingham boxlock?
If the stock is done right, and you keep the old stock, I don't see the value being hurt much, if it all.
But the stock has to be done right. Hollands, Purdeys, Bosses, Woodward, etc - they all have subtle differences. If you're talking about a British best, you need to use a guy who knows about these differences and has done a lot of this type of work.
As for cost, I think a sidelock by a real pro is going to run $3,000+ wood.
Check with these guys:
Paul Hodgins
(435) 753-2796
Leslie A. Paul
905-721-1876
OWD
