The Inkwell illustrated in British Glass Between The Wars, is shown here
(and that page is part of my article
on some variations of Ysart (or not) millefiori inkwells).
That inkwell was formerly in the Ian Turner collection. When I spoke with Ian about it, he confirmed that the description in the BGBTW catalogue was indeed based on hearsay (hence the use of "said to have been" wording) and we both considered that 1950s may well have been a more accurate dating rather than 1930s.
The BGBTW catalogue described it as Monart shape code ZG, which I believe is not an inkwell. The ZG data states only one size, 3.5 inch high, but the inkwell is 4.5 inch and the body has a much "squatter" appearance than the ZG bottle, which I think is a perfume not an inkwell. In fact, I think that there are no inkwells shown in the Monart catalogues, but that inkwells were variations based on at least one of several Monart shapes.
I have seen inkwells, by Paul Ysart and Salvador Ysart / "Vasart", that could easily have been based on any of the Monart shapes: T, WB, HE, IE, ZG, SI, EJ. What I have never seen so far is an Ysart inkwell with the main body section having surface decoration.