In the Swivomatic years, the snares were similar, but with the usual solder holding the wires in place. Sometime in the Fullerton era, Rogers invented the technique of using the heat sensitive brown resin in lieu of solder. Note that John Cermenaro, the last Rogers employee and the company's R&D man at the time, was in awe of the process. That was in the early 80s.My 1977 Dynasonic has these same style 19 strand wires. Wasn't sure if they had this style in earlier years.