Dear hopeful of the GMB....
back in 2007 Bernard Cavelot posted a Henry Greener canary yellow u. toothpick holder tumbler under Rd. 182002 - having now looked at that piece Mike, I don't see any connection with your glass, and although 'suites' could be quite large in terms of variety of shapes, I don't see 182002 - dated 20th October 1891, being anything related to yours. Bernard's item shows a simple pressed grid pattern possibly imitating cut glass - is this the pattern on the biscuit barrel you've been looking at?
I get the impression that in the C19, manufacturers were more conscious of one Registration for one shape or one design (this did allow for multiple shapes, but each carrying identical design) - I don't think there would have ever been a single Rd. No. covering more than one design.
Unfortunately, I don't have any Kew pix for 182002, but will try to remember to look at a later date.