as I began re-reading this thread, I found myself unable to support Neil's comment - somewhere near the beginning - where Neil commented that 'matching Nos.' started in the "early Victorian period" - so we're talking here of c. 1840 ish -- I can only say that, having seen zillions of these things, this is not my experience at all.
I honestly don't think I've ever seen these Nos. on a bottle older than c. 1880 - 1890.
Many years back, whilst on hols. in north Wales, I encountered a decanter collector - who was about to make a purchase of a bottle - and rather flippantly I said "don't forget to check the matching Nos." - for which I was criticized heavily. His reply was that in the earlier part of the C19 they didn't go in for such things.
From memory Andy McConnell's book doesn't give any useful dating on this practice of matching Nos.
On the other hand the digits or initials of someone's name, enamelled on the stopper and base of a bottle, may have a much older history, and probably do only refer to the pattern of the piece, or simply indicate the signature of the decorator - and is likely to have been more common on pieces from eastern Europe than elsewhere. On the few pieces I've bothered to look at, I seemed to get the impression that stoppers for bottles with enamelled matching Nos. etc. didn't fit very well. Perhaps it was just me looking at cheap Bohemian bottles
I'll have another look at Andy McConnell's book to see if it helps at all with this question.