Lots of people figured the 54-year-old Gibson Les Paul electric guitar would fetch more than its $20,000 to $30,000 pre-auction estimate, but no one knew how much more. The answer: a lot. Two Saturdays ago, Gil Southworth Jr. paid $140,000 for the guitar I wrote about recently. Add in the premium paid to Quinn’s Auction Galleries in Falls Church and the price tag came to $165,200.