Yes, Dr Kruger is a brilliant source of info., very knowledgeable, and the nicest guy you could wish to meet. He once treated me for renal calculus at my local hospital a few years ago, so I speak from experience.
Unfortunately, the forum had to suspend public write access when one of the moderators died unexpetedly. The forum was getting the blame from family members for its advocacy of fasting as a health-enhancing modality, even though there was no evidence that the moderator was fasting at the time, or that his death was fasting-related. The forum just became an easy target because it's a well-known fact that fasters are immortal, never die, and never have any other health issues that might account for their demise.
Having said that, I believe it is still possible to put questions directly to the doc., and this notice on the home page tends to imply as much:
Please post here if you specifically need a Medical Expert's Opinion on your health or fasting related issues. The Fast Doctor will reply time permitting but please please read the FAQ and forum topics before you post as you are bound to find your answers on the FAQ page. And if you have benefited from The Fast Doctor's support please consider purchasing his e-book: Health Won as a token of your gratitude.
...so it's worth a try at least if you still have specific questions that remain unanswered. You may not get an instant reply, but he should reply within a couple of days or so. You may have to open an account to make contact with him, but that should be no more than a formality.
Otherwise, if you type the word 'diabetes' or related key words (such as ketoacidosis, hypoglycemia, etc) in the search field here:
...not forgetting to define your search parameters, you might be able to find the answers you are looking for in some of the other threads. This is a fairly extensive resource with answers relating to practically every health issue, so it's unlikely you have even begun to scratch the surface yet.
As for the book, the same notice copied above suggests it's only available as an e-book, and I assume you've tried but failed to obtain a download. I can make enquiries for you about its current status if you're still having problems sourcing it. I have a personal contact who might be able to 'connect' you with a copy.
Just let me know, & I'll see what I can do for you.