This is my first Spratt Patent LRI, purchased at the Denver, Co NIA National in July 1979. Read my ICON post from today for some recollections on that great insulator show. I have since picked up more of this style of Spratt, but I can identify this one based on a unique base flake. I purchased this one from Bill Dreggors. Still a favorite. I've called this style 'regular Spratt' because it was the style I saw most often over the years.