Hi Ben,
Too late, yep that's the filter I just bought. /forums/images/graemlins/crazy.gif After reading your post I pulled it apart. It had some sort of sealant on the nuts and may not have leaked if I hadn't taken it apart, ya right. You are spot on about this being a poor design, no way is it going to seal if I put it back together.
Came up with a fix after thinking about it a bit. Made a couple of tapered copper washers using copper tubing and a flair tool. After I flared the end of the tubing I left it in the holder, used a drill press and ran a 1/2 inch step drill down the inside of the tubing. This cut the flair off the tubing and left a tapered copper washer that just fits over the stud holding the thing together. Cranked down on the nuts and no leaks, at least now I can use it and it was a pretty easy fix.