Here is a very nice Conn 12B trumpet with the Coprion bell. The serial number 320157 would date this one to 1937 which is interesting because Conn said they didn’t invent the Coprion process until 1938. There have been several other 12Bs found with 1937 serial numbers though so it’s been known to happen. It is in good condition. The “Clickless” valves are smooth and fast with no plating wear. All the slides work well. Some areas have been neatly resoldered and there is some lacquer missing as a result. The remaining lacquer is all original. There have been some dent repairs along the bell with some lacquer loss and some small dings remain. The stop rod for pulling the main slide to A is missing along with one of the guides for it. It plays very well with a strong clear sound. The original case has wear but is in pretty good condition with good latches and hinges. The handle is missing and the handle on the end is broken. It has an original Conn 4 streamliner mouthpiece that is gold plated. The mouthpiece is rough though, the gold plating is worn off the rim and plier marks on the body.
