More feed-back.
There were three plants during the post-war period, Lemington, Chesterfield and Harworth.
As I understand it, most of the mass-produced domestic ware came from the Chesterfield works. Not clear as to Harworth, but Lemington was in the main an industrial/technological glassware works.
However, it would appear there was a very limited production of hand made domestic ware, at Lemington in two categories, 24% lead crystal glass, and 31% Pb. As I understand it the latter was reserved for very limited production, usually for presentation, and ware was produced in quantities of of 6 -10 boxes, ie 36 -60 pieces. Subject to confirmation, the set I have is of the 31% lead crystal.
Having tracked down four of the senior management of the period, I am now awaiting futher information, which will be posted here on receipt.