Gold May Be Watch Band Engraved With MADE IN U.S.A. CARMEN 4x0 THE D.F.B. CO. Is It Real Gold?

Your piece is gold filled . The markings do not indicate whether it is 1/10 th   or  1/20 th  gold filled , but my guess is 1/20 th . It is an older vintage piece , and has some resale value as long as it's in fairly pristine condition.  You can probably find your exact piece or a similar one on Ebay to determine its worth.

Most commercial jewelry is marked 10K, 14K, 18K, 22K or 24K. 24K is pure gold and since gold is a soft metal most jewelry is not made of pure gold. If it is not marked with one of these markings then I would suspect it is not gold as even gold plated commercial jewelry is marked with one of the above and something like GP for Gold Plated or GEP for Gold Electro Plate. You can always take it and have it tested at just about any jewelry store of pawn shop for free.