Totally forgot to post on the blog thing here that I added a page on Old Norse Pronunciation, covering several different points in the development from Common West Norse to Modern Icelandic.
I said it on the page and I’ll say it again here: 100% technical accuracy is highly unlikely. But it’s also not a shot in the dark. Using historical linguistics we can, to a large extent (with a lot of help from a 12th-century Icelander’s description of his own language) recreate the phonemic structure of the language (that is, not the actual sounds, or phones). Within that structure there is plenty of room for both temporal and regional variation. However, the changes that are noted are likely the ones that, once they happened, stuck and spread, making way for future developments in the language leading to the Icelandic that is spoken today.
So no, this is not perfect, and even if it were, I would have no way of knowing, but I feel relatively confident that it’s at least an improvement over most of what can be found on the internet and definitely helpful for a student trying to understand the relationships between sounds.
If anyone has any questions or suggestions, feel free to let me know.