Reddit reviews Old English: A Historical Linguistic Companion
We found 2 Reddit comments about Old English: A Historical Linguistic Companion. Here are the top ones, ranked by their Reddit score.
Used Book in Good Condition
The two resources already mentioned, (Crystal and Millward), are both too vague to help I think. I'm not sure about the Crystal one, but the Millward treats Old English as a uniform standard (that's not a criticism of the book).
What you want is something like Campbell's Old English Grammar. There is a detailed description of the various sound changes that occurred just prior to and during Old English, and in the grammar section, after recording the West Saxon norms, it gives the dialectal alternatives as well as chronological changes.
The book is old, but still the standard. More recent and excellent are this one and this one, but it's been a few years since I've read through them so I can't give more details.
Other than those, much of what you are asking for is found scattered through various books and articles, but they are all for specialists (as are the ones I give above), so they might be tough to get through depending on your knowledge of the field.
http://www.amazon.com/Old-English-Historical-Linguistic-Companion/dp/052145848X
I got this book because of interest in Old English and was delighted to find it included a lot of background for the Proto-Indo-European and Proto-Germanic languages from which it developed...I think it would be right up your alley.