Hi Lars,
It seems that formatting is hardcoded into the revhistory template. I'm afraid you'll need to customize the template to remove those attributes.
There are actually two templates with match="revhistory", one in html/block.xsl and the other in html/titlepage.xsl. The latter is used when the revhistory is in an info element.
Bob Stayton
Sagehill Enterprises
bobs@sagehill.net