Hello All,
Firstly, I think it is reasonable to point out that these glasses could have been a design used at one of three exhibitions which happened from 1934 to 1936. "Modern Art for the Table" - Harrods, 1934; "Art in Industry" - Royal Academy, 1935; or, "Everyday Things" - RIBA, 1936. (Edit) - There were extra designs added to the later exhibitions, so it may not come from the Harrods one.
The best place to approach would be the Wedgwood Museum as they have the Stuart archive. If you send them clear images - profile, detail of pattern, base - and give them sizes, etc., they will look up the archive if you point out that they are marked with a facsimile signature which suggests any of those exhibitions. Give them plenty of time as they are (like all museums) short staffed and can't 'jump to it'.
The catalogue for the Art in Industry exhibition does not help at all as it is not illustrated and the descriptions are limited to what the item is, rather than the decoration.
I'm afraid, IMHO, it is very unlikely that you will find a replacement easily, in fact it could take years, or even never happen as no-one with a set will want to split it, and given their likely rarity, you may find one I'm afraid. Certainly I don't recall ever seeing this pattern before. That said you may have extreme luck and find one next week in a charity shop!!!
Oh, and I don't think this is Woodchester pattern, or a prototype, rather more it is a pattern that stands on its own as part of a theme that Ludwig Kny explored over time. Also I think it is a likely pattern to re-occur given that designers were looking to pare down the patterns used in the Victorian era, hence the apparent duplication(s) mentioned above.
Cheers, Nigel