I feel like I've seen them here before.....  

I don't know if anybody knows what the numbers stamped on the frames of Møller chairs means. I do have one that actually does have the date stamped on it, but that is definitely an exception. I have seen dozens of others without a date.
These chairs date from before 1971/72. I know this because of the metal medallion, which Møller used before then. Afterwards they started using an ink stamp and were much, much more reliable about actually stamping their product. Earlier a lot of the time they did not mark things; fortunately their stuff is well known and easily recognizable.

Thanks Leif! I was asking too much regarding the original upholstery, the black leather had been cut away, leaving remnants. Oh well!