No there is no list for stencils. The best way is to try to match it to another horn . If its split bell keys it will be a true tone, same sided it will be aristocrat. I have only seen one knickerbocker and that was a true tone with Aux front F so it would have been built after 1926. Dave

Dave, it does have split bell keys and an aux front F, indicating it's a Buescher, but my sons sax teacher pointed out that it has beveled tone holes which he associates with Martin, not Buescher. What do you think? And by the way, thanks for your time. Scott

Well knickerbocker was a stencil made by buescher but with bevelled and soldered on tone holes that was a martin build, two things , martin may have built horns for the same buyer as it went on who had the cheapest price at the time so buescher could have made a batch then martin . Secondly some stencils have been found with bevelled tone holes but buescher or conn built so a collaboration may have taken place as they were all in Elkhart so at least you know it came from a good factory Dave