Nyman was my first thought, being the only GN glass designer I could think of, but there's no record that she ever designed for Boda Afors.
But I think kisslikeether
has got the answer anyway. I went up to photograph the items, and the first one I grabbed definitely had GN... but then I looked at all the others and they were GH.
Typically, the first one I looked at - the only one I'd looked at until that point - had distorted lettering (the one on the left in the photo below).
Ernest Gordon it is, then. Thanks.