Paul,
Hi, yes Ernest Gordon Afors signatures can be a bit confusing !
this one I believe is GH 3137 24 (cow parsley).
there seems to be two main sets of engraved plants/animals with GH on them; a run that starts from GH 926:1 to GH 942:17 (both sets of numbers go up by one each time).
Then we get a few larger ones around GH 943:16 to 947:20 (bit of number overlap).
Then as you spotted there's a small sequence around 3137; 24 (anemone), 25 (thistle), 26 (snowdrop), 27 (cow parsley).
I've been collecting his bits for 15 years, so if there are others in this run they are very uncommon.
the numbering can go a bit awry, more so than Kosta - I've got one bit (and there's another on Ebay) where they have signed them but not got around to engraving them - I'd have thought they'd have done it the other way around, so you do see bits with the wrong numbers on.
I agree with the GH/GS/GG above. On his Kosta pieces (much less common) in addition you'll also see GD, which is also engraved. You'll note the similarity with Kosta Lindstrand numbering (LH,LG,LS).
if you search through the archives on this site you'll find some other posts from me with afors and Kosta Ernest Gordon pieces.
Regards
Gareth