Hi Tab,
Interesting find and I'd have dropped the coin too. Was this vacuum sealed? (explains a lot including possibly dating). Was the tobacco moist when you opened it?
I expect that the bag, based on the quantity, was a custom mixture for a tobacco store, quite possibly 1Q with some additions as noted (somewhere else) in the thread. 5-lbs would be about the minimum that any tobacco vendor would custom make. Possibly a sample to test in a store with, hopefully, larger quantity to follow if successful?
The earliest that this tobacco may be from is about 1990, (based on this link):
California Anti-Smoking Legislation (search for WARN). This is when California legislated this wording of the warning label to appear on cigars (and I presume pipe tobacco). Obviously it could be anytime after this. Dunhill bought Lane in 1976 (according to this link):
Dunhill discussion (do text search, ctrl+F, for LANE). The custom (part) of the printing on the label, "My Mixture 28,000", "5 LBS" and "C091" appears to be dot-matrix printing, and I suppose that "C091' is a product code. My Mixture 28,000 sounds like a Dunhill moniker.
I have no idea when, nor if, Lane used Vacuum seals on their bulks (if this is indeed sealed that way) but if so that would probably push this into the mid 1990s. The label template itself, (without dot-matrix), appears to have been made before use of computer graphics. but obviously not before 1990 (because of the California warning). By today's standards, it's an old style of label but they'd probably have used them towards exhaustion. Lane was sold to Rothman's (per the link above) in 1987 but it's likely that little changed for some time after any acquisition especially if they continued to trade under the Dunhill or Lane names (as the My Mixture would indicate).
Dunhill owned >=1976 and <=??
Tucker Georgia manufacture >=1983
California Warning >=1990
Probably a PC-based, dot-matrix printer labeling system, >=1990 (could have been earlier but doubtful especially in the tobacco business).
No bar code <= 2005 (or a bit earlier).
If I had to venture a (conservative) guess I'd think the bag to have been packed in the mid to late 1990s.
As far as My Mixture #28,000. Dunhill kept a book at their London store that cataloged all blending (done in the store) and each custom mixture, for or by smokers, had a number. I'm in the book in April of 1980 and my number was something like #9365 (don't remember exactly) but until 2000 (or later) it would have been impossible to track custom mixtures across the pond and back (needed WAN or Internet as well as the application) so I expect that, if they were careful, they assigned blocks of numbers to different sourcing areas and #28,000 was either the next number that could be used or the next round number because they had no real idea of what number to use (probable) and just jumped ahead.
Sounds like there was (a lot of) cased burley in the mixture and I believe that someone mentioned that there was some Perique. If the tobacco was vacuum sealed and under pressure then the ageing (marrying) would occur more rapidly and with those components things could get quite messy. I have a tin of Elephant & Castle Isle of Skye from 1985, (>10% St. James Perique - the original stuff), that I opened and allowed to dry in 2000 and then re-hydrated starting in 2013. The tobacco from the top or edges has been spectacular but the tobacco from the middle (more heavily pressed) is a flamethrower and a muddle. The Isle of Skye is a VaPer so the impact would probably be even greater with burley (and aromatics) if under pressure. Even the weight of the bag would cause pressure in this case.
Please let me know if it was a vacuum seal because that would explain a lot. You paid less for 5-LBS than many pay for 50-grams in an aged tin. Sorry that it's not been good but you were intrepid to buy it.
You might want to call Lane Ltd., explain your story and then send an email of the label to see if anyone there could help you more clearly identify the blend and time frame.
Regards,
Pete