The IPA in the book is for your average home-counties RP english textbook sort of voice, and I'm from Kent, and describing variations in accents with IPA is not my strong point at all. My accent's not that far apart from that in the book, but there's the odd sound that's different. With most of them, I've made the students aware from the start that I don't always pronounce things the same as the textbook (and also introduced ɫ / dark l from the start, because they need it for that), but my brain has gone totally blank for what the hell to write for the sound I produce for that particular one. I think there's a w in there somewhere, and maybe a ʊ, but I really don't know. Here's a sound sample of total nonsense (please excuse my voice for sounding bloody awful)
Can anyone help?