TC25-263 COMBINATION BUTT AND MORTISE GAUGE. Thompson Patent. These uncommon and attractive gauges are either unmarked entirely or simply marked "patent applied for," but the consensus is that they are examples of Thompson's 1900 patent. See Bachellar, page 112. This example is beech and brass, closely resembles the patent in that it has knurled brass locking screws rather than the thumbscrews more often found. Overall wear but no damage, points sharp. Good 50-100