Do they need to fit the wing tip or winglet? I think it is the first, If you look at this picture http://www.airliners.net/open.file/542488/L/ you see that there is al light on the end of the tip and at the pictur in your reply there is none. So I think that they need to fit a small wing tip iso winglet.
Would be nice off course to see a DC* with winglets but to be honest a think Dave made the wright conclusion.
They need to refit the wingtips and not the winglets.
It's also mentioned that they need to refit these to the plane and as far as I know ZS-OSI didn't have winglets before.
But never say never. There's also a 707 flying out there wich has winglets fitted to it's wings.
I thought the photographer made a mistake in writting his comment, but I was not shure. When about 5 years ago, spotters at Ostend began to say a 707 with winglets would come to EBOS, I thought they were nuts ...
How wrong I was ...
That's why I didn't know if the photographer made a mistake or if was just very well informed ...
As you all allready said, it will probably be the wingtips ... but you'll never know ...
Andries 
hmmmm, i prefer they let these "old lady's" as they are.
