The photo you (OP) posted of the wingtip with the "curled" trailing edge is not a stock wingtip. It appears to be a RMD wingtip, which until recently was manufactured just 5 hangar rows up from me. The business was sold in August to Knots2U, which is where they can be sourced from now. They might be willing to provide you just a lens if you ask and if that's all you need, not sure. But, there's a lot more to building in wingtip lighting than that lens, of course.
Here's a link to the actual wingtip you asked about:
http://www.knots2u.net/rv-4-6-7-8-wing-tips-w-landing-lights-set-of-2/
Nice people there, very helpful when you speak with them. The wingtips are well-designed and well-built. The nav/strobe/position light pad is sized for
Whelen 600's or equivalent (650s work fine too), which are available from Vans Airforce sponsor Mike/Kahuna over at
http://teamaerodynamix.com/ (highly recommended). I also got my LED landing and taxi lights from Mike, and swapped out the old-school bulbs with the new LED ones. The landing/taxi light in the RMD/Knots2U wingtip is very adjustable/aimable on a spring-loaded "floating" mount mechanism.
Vans has provided a few different wingtips over the years. The original W-415 (flat top) wingtip doesn't have a lighting cove and the wingtip landing light modification kits that Vans sells don't fit that one. I think there was an aftermarket one at some point that I saw, and of course people have done various fabricate-it projects.
I have the RMD/Knots2U wingtips on my Cherokee and was happy enough with those that I now also have a pair of them in my build shop, which are going on my in-progress RV-8A. I may use the old 415 tips for some camera projects I haev dreamed up, we shall see. Gotta finish this project and make it a flying airplane first.
Hope that helps. Here are a few pics of my 8A project wingtips from when I was installing LED lights, etc.