This is an early model 36B Conn Constellation trumpet made sometime between 1959 and 1963. The main factor that determines this is the fact that the horn does not have a 1st valve tuning slide trigger. Later model 36B’s had 1st tuning slide triggers. The 36B is the “lightweight” version of the 38B. The 36B doesn’t have the heavy bracing that the 38B has; its bracing is lighter in weight. The 36B’s bell diameter is also slightly smaller than the 38B. The 36B has a bell diameter of 4-5/8″ compared to the 38B that has a bell diameter of 5-1/8″. These couple differences are the two big factors that differentiate the two models. Most of the other features on the horns are identical between the two models. For example, the bore size on the two models is the same.