The lock ring on Ebay http://www.ebay.com/itm/142015687206?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT these were available from dealers until fairly recently.
Agreed these are NOS but later issue. Does anyone have a source for the correct 1969 style ring with the "shorter gaps"? I could use 3 of them NOS.
