FYI - I was just looking around for long-travel crayford-style focuser for a refractor I'm going to build and came across these billet aluminium focusers out of the USA. They look very nice and are reasonably priced. Best of all they do a refractor version that has 4" or travel - nice! I have not seen them mentioned on IIS before - hence the post.
http://home.comcast.net/~wyorock/wyorock.html
Cheers
Chris