I've only just looked at this as I'm rather wary of topics with titles in all capitals. Anyway it's OK, or, perhaps I should have said, ok.

I'm 100% certain who made this vase, because it tells you. Suppose you want to call a range "Rex", a popular brand name during the mid 20th century. You can't call it just "Rex" on its own, as it might get confused with PYREX, and Jobling's directors and senior management might get rather upset, quite justifiably. So you do a portmanteau job on it with something else quite different to "PY". How about, for example, combining it with your company initials?
Do I need to spell it out?
Bernard C. :angel:
ps — any chance of a photograph of the mark, please? How does the lettering compare with the mark on my 1938 Raybould Tazza (click to enlarge):