If you want to gain a perspective on custom rifle resale value, take a look at Hallowell's website below. Figure the cost to re-create some of those rifles in today's dollars.
Hallowell Custom Rifles For SaleThose are some nice looking rifles! A.O. Niedner's 86 year old great-nephew is a member of my congregation. I'd love to have that old 7x57 to show him some of his uncle's work. I wonder if the stock is a Shelhamer stock.