I used to have it too, Peter Gurney's website is still there even though he is no longer on this earthly plane I think its kept as a memorial. Theres a lot of information on there.
I think that since he was writing, vets have become a lot more piggy savvy, so I have found there is not the need to rely so much on his books as the only source of information, or maybe I'm just lucky with my small animal vet as he is a rabbit and piggy enthusiast? 15 years ago piggies were given the death sentence much more quickly by vets and I felt like the Pete Gurney books offered the only alternative.
Somone else might come along and tell me I am wrong though...........
If you are looking for lice treatment and neem oil preparations I can recommend Gorgeous Guineas!