I found some good advice on handling dead links and one of the pieces of advice is to fix the link if possible.

In the situation where the link is dead and I can correct the link, can I strikethrough the original and give the corrected eg <del> or http//news.com.au instead?

I figure it shows that the link has changed, should anyone wonder about the original site.

Edit: Example of where I have tried to do this: http://stackoverflow.com/review/suggested-edits/2911883. In this situation the original blog is no longer live, and the author uses a new address.