An alternative place to contact might be the Guild of Glass Engravers?
The theme is one used on a lot of Caithness glass, they did have a lot of very good engravers working for them, although I do not think they were exclusive. The engravers could engrave elsewhere and in their own time, and many did when Caithness was not producing so much. I have visited the Caithness visitor centre in Crieff for years, and have even bought an engraved bit by a former engraver, now working on her own. A little cream jug showing a bumblebee bumping into a dandelion seedhead.
https://www.gge.org.uk/