You may wish to get in touch with Fred Holabird of Holabird
Americana. His web address is holabirdamericana.com and his email
Fred was originally a Geologist that specialized in gold mining but
now runs a company in Reno, NV. that auctions gold mining and western
His staff has a broad knowledge of Gold Mining History.
By the way, although your bar is fairly recent, many of the gold
bars marked with names of Western U.S. mining companies that date
from the 1800's bring very large sums of money.