Anyone have luck with a replacement radio antennae? I've tried a couple "off the shelf" at auto parts stores with poor luck.

Get a Hirschmann antenna. That's what I have had in all of my 914-6s and what I have for my '71 Six.

Here's a link to the Hirschmann I'm going to get soon.

http://www.ebay.com/itm/351598669678

I use a Meta brand automatic. Works great, fits and looks proper.

I've had a Hirschmann for years and it's worked great.
I like it because I can lower it when I put my cover on
and when I 'm driving I don't extend it all the way up.