In case anyone is interested/considering one of these: I've just taken delivery of a Crafter Blue rubber strap made for the "new" Seiko Samurai case - it's really good quality and fits the case perfectly. Doesn't seem remotely like a lint magnet either, which is nice!
I'm not entirely sure about the rather cheesy "Professional" engraved on the steel keeper, but other than that it's ace: supple, comfortable and sufficiently long that one could easily put it over a wetsuit if one were so inclined. It isn't quite as retro-chic as an Isofrane but to my eyes it suits the Samurai's modern, angular case very well.
Untitled by preachercain1, on Flickr