This item is a beautiful THE Martin Committee trombone built sometime around 1945-1946. The serial number is 150505.
This is made by the same craftsman that made those legendary WW 2 era Martin Committee Model trumpets, at the same factory, with the same raw materials. 
This truly "Vintage" instrument has been professionally serviced, thoroughly cleaned and sterilized, tuning slide lubricated, hand slide aligned, and a new water key cork. All minor dents were removed. It includes the unique, original style mouthpiece with all silver plating intact.

Here are some unique features of the Martin Committee Model trombone that you can see in the pictures

Here are the negative issues: