Ah, this is the Dowl, sometimes called a Bish... ahem...

Sorry, my cronky eyes saw that as 6-in+, not 7-in+ and so this is the interim size, and as you rightly say not recorded in
Chance Expressions. At the time of writing I recorded that size on p.38, but not in Intaglio. The following is correct:
No. 16 7½-in (19cm) Nut Bowl
So the full range of Dishes and Bowls as taken from a 1969 catalogue is:
11. 6¼-in (16.5) Fruit Dish
16. 7½-in (19) Nut Bowl
12. 8½-in (21.2) Fruit Bowl
51. 10-in (25) Fruit Bowl
32. 12-in (30.5) Bowl
Because moulds never changed (apart from the radical design swing in 1969–70), these sizes would be pretty close over the years and would never alter that much (the odd +/- ¼-in would be the most I suppose).
The trouble with the quoted measurements is that Chance rounded it to the nearest ¼-in, and they would inevitably alter slightly from batch to batch. So I was either measuring examples or being quoted dimensions by other people, and that leads to some minor discrepancies. I'll be re-issuing tables in
Chance Additions based on the catalogues now that I have this documentation.