Stumbled across this on the web. I have no affiliation, it just looks
like a cool tool if you've got a lot a baseboard to install. OTOH, it
could be a piece of junk.

In brief, you make a mold of your baseboard's profile and use it as a
template to guide a router.

http://www.thecoper.com/detailed_instructions.htm

There's videos available at the site.