Actually, after just reading up on RTF (check out
http://search.cpan.org/~sburke/RTF-W...F/Cookbook.pod), it looks like the font size command is doubled, so fs24 would equal 12 point font.
Doing a bulk modification on RTF docs should be incredibly easy, as long as each document follows the standard. I'd read up on the prior link and it shouldn't take more than a few minutes to throw together a script. I had no idea how simple RTF was as I never use it for anything.