This will fix relative paths, download assets, etc and can be published as-is on a new site. I'm ignoring copyright questions in the interest of archiving fragile data.
Then I'd use an HTML parser against the local archive to extract the individual posts, if the additional work was justified.
I used to use this to mirror Slashdot when I was travelling for work and had limited/no internet:
```
wget --ignore-length --no-remove-listing --no-check-certificate --recursive --page-requisites --span-hosts --convert-links --no-verbose --tries=3 --timeout=60 --level=1 --user-agent="Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0" --html-extension --exclude-directories=my --directory-prefix="./slashdot/" -e robots=off --cookies --load-cookies slashdot-cookies.txt --keep-session-cookies http://slashdot.org/
I suspect that still works, just needs the user-agent updated.
My memory says there was a project to be a vB->Discourse converter that didn't rely on DB access, but I can't immediately find it.
God, why? I can't be the only person to find Discourse inferior to vBulletin.
While I'd agree that Discourse isn't ideal, it's one of the better options available in the open source world.