I'm selling my son's King 2103 3b He used it thru middle school and in high school jazz band. It's all gold and from the serial number it was manufactured in the mid 1940's. I had it checked out at a local trombone shop and they said it was in good condition and the slide was fine but it needs cleaning. The instrument is almost 70 years old and has some scratches and minor dents. Can anyone advise as to what a reasonable price would be?

Thanks

It's hard to say, but as far as I know, King wasn't calling the 3B 2103 during the 40's. If it really is a 40's 3B, and it's in good shape, I'd say you could ask 500 or more for it, but it really depends on the condition. If the bell says 2103 on it, it's probably much later than 1940s.