In regard to the Stealth's with a longer foot than the Blade which is approx 225mm shorter, I'm only aware of two versions, the original MK1 and improved MK2 with a bigger fat head. So the Blade Landy mains are a totally different animal which have a higher aspect ratio. I'm not positive but the two Landy Blade mains that I've seen do not look that similar. Hans's and Paul's leeches appear to be different shapes and Paul often sails with his original (Ullman?) main when single handing using his Landy only when 2 up.
So to answer your question Rolf, yes there are at least 4 differing types of Landy F16 mains available which I know of.
I'm affraid I still haven't got round to learning how to post pictures since this forum's upgrade but if you have a look at the 2007 F16 World Championships pictures on the Mumbles Yacht Club website (especially one of the line up shots from the rear) you'll notice that Hans's main is pretty much unique and if your very observant I'm pretty sure his yellow kite is also a Landy one off (MYC website 2008 gallery F16 Global Challenge). I'm not convinced it's a good kite! but I'm usually so far behind by the time I get to see it up I could be wrong [:-(]
http://www.mumblesyachtclub.co.uk/index.php?menu=photos