Bloodstock agents Sean Feld and Chris Brothers have plenty of experience flipping horses in the sales ring, but this spring they're trying their hand at flipping burgers as they venture into the restaurant business. Last month they took over Charlie Brown's Restaurant and Lounge, a beloved dining staple in Lexington for decades. Feld and Brothers are longstanding regulars at Charlie Brown's. The cozy, pub-like spot has been in the hands of David Fuller for almost 40 years. When Fuller decided to retire this year, he passed it on to longtime...