> Any offer guidance on how to remove certain messages from a lists
> web archive?

It's not really that difficult.. but you do need two things.. an
email client that will allow for message bodies with wide margins..
and a text editor with the same.. both may need to be able to accept
a very large amount of text too.. depending on the size of your
archive.

Then go to

http://www.skally.net/listowner/archive-edit.html

for a fairly easy to understand "step by step"