'Ysolt' really translates the German version of the lady's name 'Isolt', which the French horribly mangled into Iseult.  I don't think that Caradar knew that the name turns up in an ancient 10th century place-name in St Keverne parish: hryt Eselt, 'E's ford', which gives us the Cornish form.  Eselt descends from British ad-siltia, 'to be gazed upon'; the Celtic equivalent of the Greek name Miranda.

Karesk, I did post a response of thanks to you, but it seems to gone astray. I ended up buying that copy on eBay with much joy, as it's one of Caradar's major works, and one which I hadn't read. I already had the concluding section translated after Caradar's death by Carer Brynyow (iirc) and which, ironically, is much more often available second hand on the Web.

For anyone who might be interested, there were a couple of copies of Caradar's translation on sale on Amazon UK last night, although the price was a bit higher, alas. I think there were also some of Carer Brynyow's part as well.

Gromercy dhys unwyth arta, Karesk whek!