There should be a serial number black ink stamp inside the snare mid-way up the side of it- away from snare fastening and muffler hole positions. Most of these Pippers were vertical grain birch veneer on the insides and out with mahogany the middle ply. Reinforcing rings should be European Birch. We have a Facebook site Ajax Drums? Where you can compare serial numbers. My snare serial is 50185 and that is thought to be around 1955-6