Lawson flares are getting harder and harder to come by. Ones in this condition are even rarer! This is an Ambronze, Pattern Annealed flare, serial number 874L. Lawson was the first maker to use Ambronze when building horns. Between the weight and the material it gives them a special sound, and it's a sound that doesn't 'edge out' very easily. That is one of the hallmarks of a Lawson instrument or flare.
There is some lacquer wear on the inside and a bit of water staining, but overall it's in great shape.