This is the standard American format, with 3 valves and a curved (adjustable) bell. The serial number places is as a 1940 model, so the pitch should be based on 440. It appears to be silver plated with a gold wash inside the bell, and the plating is in good shape except for needing a polish job. Original case is included, although it has some wear (a little black duct tape might be a good idea around the bottom seams). Starting bid is $150 and shipping is less than $40 (from WI).
https://www.ebay.com/itm/Buescher-El...6/114431775263