Thanks for your suggestions, all. I just talked to Ryan at MLBS and he does have these in stock. Apparently they are changing their stock numbers which is why these don't show up on their online catalogue.
Mitch, I did confirm that the octagon segment tapers slightly to the wedding band, and the round muzzle flares slightly. I think it'll look very graceful.
Daryl, nice job-- if I had a metal lathe, I'm sure I would be "rolling my own", but in lieu of that, I don't want to work an octagon barrel down to round by drawfiling. (I'm just a mortal who's not afraid of kryptonite.)
Gregg