This is almost the same aproach I used for Bloxp[0]. I have some common Previous Post link markups and I try to navigate from the last post in a blog, one by one, to the first. I also allow to manually indicate the HTML markup to use for crawling a given blog, in case it is not matching any of the common ones.

I uploaded the site 10 years ago (at first I did it because it was useful to me) and I have made almost no changes since then but many people still use it as a simple way to export a full blog into an ePub.

[0] http://www.bloxp.com