Elk City and Weatherford have modest route 66 museums.

Philbrook and Gilcrease in Tulsa are renowned art museums.

Conoco museum and Marland Mansion in Ponca City

Phillips 66 museum and Woolaroc in Bartlesville.

I would be careful engaging with the gentleman from Tulsa who often list several rough signs on Craigslist.

Collect small Oklahoma Oil Co.'s 1920's-1940's. Barnsdall, Cushing, Eason, Marland, etc.