John,
Not long ago, you should have fully expected to lose up to 15% of a page's SEO equity with a 301 redirect. That changed in February of this year when Google's John Mueller announced that no page rank is lost with 301 or 302 redirects.
Moz's own Cyrus Shepard wrote a What You Need To Know Post after that announcement. I think if you read it, you'll be well equipped to weigh your options and decide on the best path forward for this particular situation.