I don't get the impression, certainly from looking at shed loads of decanters, that the positioning of 'matching' numbers is of any significance - however, I might stand to be corrected with regard to scents/colognes. With decanter stoppers, the number may be on the end of the stub, the side of the stub or even the neck of the stopper. As far as the bodies go, they maybe on the top of the flange, the underneath, the inside or the outside of the neck of the body, and even on occasions actually on the very bottom of the body. Of course, unlike Baccarat (for example) the Nos. on decanters are purely marriage Nos. (matching Nos.) and as far as I know do not signify any specific producer/year.
I found your link very interesting m - because the attached pictures are of a u. Baccarat scent, and I thought for a moment that the list would give a year date for this piece, but unfortunately not, and as the preamble says the list is not complete, so no conclusion and can only think it is post 1936, possibly. Irritatingly, the Baccarat method of numbering seems rather haphazard, so can't make educated guesses at dates. I hope you don't object too much to me showing these pictures on your thread m, but thought you might like to see what are obviously Continental script Nos. (not European

on a Baccarat scent - if the mods consider inappropriate, please remove.

One No. is on the end of the stopper, and the other on the base of the body. My Nos. don't seem wildy non-English - I'd be looking for a very long upward sweep for the figure 1 - but from the 8 and 9 you'd probably punt more for the Continent rather than English. If you contact Baccarat in Paris ....
patrimoine AT baccarat DOT fr [Mod: email address anti-spammed] ...hope you are successful - they were certainly very helpful to me last year. Best of luck.
P.S. Anne thanks for the expanation re my other link...........we sound like train drivers, all this 'coal on'
