OK, Bruce may be a great guy, but he doesn't have these, he just advertises them. I've checked several times, and they're always out.
So - back to my original question - is there anywhere I can actually buy one of these? Or a kit I can assemble myself? Or even just the end caps, since it looks like they'd be the most difficult (I don't have a lathe)? I'm thinking that, with the difficulty of finding these in stock I'd prefer DIY even if I managed to get to that website during one of the rare occasions he actually has them in stock, anyway. I don't want to be held hostage to the refresh button on my browser to get replacement parts. Much better to be able to make them myself.