RE: Fins for lightweight on 2005 Evo 70
If you happen to have the NorthShore Wave onshore fins (made of blue and white polyester in 2003), they have much more surface both mid-section and at the tip than the Drake Natural CNC. It could be that your Drake 205 might feel much smaller than the 7.75" NorthShore in fact ...
I think your NorthShore 8.25" is large enough with your 5.0 sail on Evo 70 for your 62 kg. FYI, I'm using a NS 8.50" with a 5.4 sail on Acid 62 (65kg) when it's light wind or when it's windy, a Select Pro Wave 20.5 cm (less surface at the tip).