Nice flask Aaron,You know the top on yours is the least encountered on these flasks. Most are just plain sheared,a good majority are LTC (Long Tapered Collar). Some have a tapered top with a large ring of glass around the base of the collar which makes the top look like a derby. Another type is a large thick ring which looks like the Green Bay Packers Cheese Heads. Others have a flattened blob type top. Your flask has the the Double tapered LTC not encountered that often,NICE FIND!! Sheared top from a Taylor Below.....