I've gotten on a recent kick of collecting older 12 YO Macallans. Unfortunately, Macallan doesn't indicate a vintage year on the bottle the way they do for the 18s, so I have no way of knowing if something was disilled in the 60's or 70's. Any suggestions as to how I might be able to narrow it down? Are there any codes on the bottles or labels that may hint at the contents' age?
I've tried to focus on 75cl bottles from Europe on the assumption the EU didn't convert over to the 70cl size until 1992. Do we know when Macallan actually used the 75cl bottles? I've asked Macallan but my inquiries have gone unanswered...
Thanks a lot in advance!

