Hans L, I am not really sure about that much of a stretch, 3 or 4 months seems like a long time. They would have had to have ALOT of wheels laying around still, and hold production while they went thru them all. I don't know, I am just speculating. They of course could not be asked for RIGHT when they were needed, so they had to have some stock laying around, but 1000's??? I think you are correct on the batch building of wheels from what I have learned from the guys on this forum. And I don't think weekly dates are available. Seems like Jan of 69' has 2 build dates, MAYBE 3. That would be 1/10/69 and 1/28/69 as you mentioned. I am still thinking I might want some 1/28/69 wheels, or even from the first batch of Feb. 69' {anybody got any?} as I now have a few 1/10/69, all "YH" of course. Oh well, the mystery continues. Good times Eh?......Danny