No worries, I was just picking up on the 1967 thing to illustrate the sorts of things one needs to think about when setting out to find "the year" when something happened. And I loved the "no beer policy". Something certainly happened to make their lathing much more consistent. Might as well be that.
Remember I'm not the originator of much of the research on my site. The originator of the pre 1970s timeline stuff is Bill Hartrick (member Drumaholic here on VDF although he hasn't posted anything for a couple of months). I'm just the doing the compilation and presentation of that early stuff as best I can. Other sites have partially reproduced Bill's work with errors and omissions, and without giving proper credit to Bill.
And as you'll see in my introductory remarks, I started documenting this stuff because Google won't find much properly referenced material which is evidence based and written from a neutral point of view. One thing I have yet to do is to see if I can dislodge (rank higher) then some of the bogus sites which come up first. But I'm still trying to build content first. Fortunately I am being helped by others out there who know more than I do.