sorry m - going to disappoint you and be negative on this issue I'm afraid, even without going to Kew. I have photographs of all (in fact I think there's only five in total) of the Richardson Greek/Etruscan images, and none appears to be a match for the illustrations on your glass.
The famous Registrations of which you speak are from July 1847, and concern Rd. Nos. 43924 to 27. These Registrations show a variety of characters in various poses, including horses, bacchanalian festivities, some with war-like adornment, tinkers and other general frolicking - enough to make you wish you been born two and a half thousand years ago, when the wine flowed and free love was everywhere.
Unfortunately, I can't see your particular designs. When I get the time in the coming days I'll send you un-watermarked copies of these Registrations for personal viewing only - trust you won't use them publicly without watermarking.

Some year or so back I did show one of these 1847 Registrations, but I forget exactly when, so have added picture now showing Rd. Nos. 43924 and 43925.
Of course if you know of other Richardson Registrations apart from the ones I've mentioned, let me know.