In answer to my original query, many fonts of knowledge have contributed – thanks to you all for your time. Have cut and pasted here for all our benefit . . .
From a brilliant copyright expert at Penguin, "the Publisher would also have to purchase the font to use it . . . This is an absolute nightmare when selling overseas rights or licensing on our covers . . ."
From another brilliant copyright/production/font expert at Penguin, "[the] freelance designer would have to hold a licence to the fonts . . . however we, the publisher would need to purchase font licences also – we would bring files in house, to print out and circulate if nothing else, to do corrections, and to archive. The repro house would also need to hold font licences. The foundries are going to do very well out of this, but it is important that we are in strict compliance will all font licences."
And from the ever helpful and brilliant art director, Deb Brash, "Foundries have had the same licences and agreements for ages, but are cracking down on ensuring that the often confusing and complex licensing agreements are adhered to."
Thanks again everyone.