Thank you for contacting Mearto with your appraisal inquiry. Based on the photographs and information provided, the subject of this appraisal is an F.E. Olds & Son Opera Trombone in silver plate, circa 1950s. The piece appears to bear a serial number of 28288. The piece is in good used condition, with some lacquer wear noted but no dents or significant damage apparent in the photographs examined. The piece is missing its original case. Based on a combination of prior sales of Olds trombones from this era at auction and current listings of Opera models from vintage instrument resellers, and subject to play testing and examination for any condition issues not apparent in the photographs provided, its Fair Market Value in as-is (non-refurbished condition) is estimated at $800 to $1,000 USD.