Fuchs
 

DK what year they first appear, but the 'hearts' are small channel on the lip of the cutout section, where the valve sits on each wheel. I think but I'm not 100% that the Fuchs with hearts and what's called Deep sixes are the most desirable, but as with everything the price asked for them reflects that.
I picked up some very nice year correct refinished 15x6 Fuchs for my 912E on this forum. I saw a couple of good sets on The Samba too recently, and of course they are on e bay.
If you want to know more info on dates I think the Porsche authenticity guide can help, its about $30 on Amazon.
HTH

Gratuitous pic of my car on the old 14.5x5


http://forums.pelicanparts.com/uploa...1231310401.jpg