"If a new stock has been done absolutely correctly, forend too, it will not adversely affect the value of the gun."
From everything I've ever seen, this is not true. All things being equal, I don't anyone who pays the same amount for a restock as an all original gun. The only exception may be a restock that letters as having been done by the original maker. If it doesn't letter, forget it.
But for a fee, I'm sure Dig knows where you can get a stock done absolutely right. Or he can sell you a restocked gun that is worth just as much as an all-original one (at least when you're buying it).
OWD