My apology to the list and thanks to Pete Paine, who wrote:
"The 12 spline cogs were first introduced in the very early = 1930s for the TF two speed fixed and disappeared in the early 1950s. A = threaded driver seems an odd thing to find on an ASC for obvious reasons"
I just checked my box of Sturmey parts, and pulled the lock ring from my old ASC driver. As Mr. Paine suggests, it is the old 12-splined driver, not a threaded one. Please excuse my "senior moment."
harvey "ready, shoot, aim" sachs mcLean va