Of course, there was the time when (presumably) they had a lot of typeface expertise in-house. Thus, The Printing of Mathematics, was by T(heodore) W(illiam) Chaundy, a mathematician who taught at Oxford, and Charles Batey, "printer to the University" - and P. R. Barrett, whose role I cannot identify, but he may well have been the actual Monotype operator in the group.

Mr Barrett was the specialist maths proof-reader in the printing division of OUP in Oxford, and, as a young proof-reader myself, I was privileged to know him there in the early 1980s, shortly before his retirement.

There was indeed considerable in-house expertise in the printing house, but the printing division in Oxford was to some extent separate from the publishing division, and only dealt with a small part of the total amount published by OUP in the UK. The publishing division (‘them upstairs’) had a considerable body of experts of its own. But that was a long time ago. :)

Thank you very much for the information! Yes, times change, and what with desktop computers and laser printers having the potential ability to put out near-professional-quality typesetting, replacing typesetters with typists was understandably an overwhelming temptation.