There's good news and bad news.
The good news is I found a simple solution to fitting a candelabra base socket into a 1/2" pipe. Just put it in there... I should have bought one when I first started fiddling the other day, but it's actually good I didn't, because I didn't find the small version without the hickey until today.
This is what I bought. It doesn't have a hickey, and was on sale - which means I paid $0.95 for it instead of $2.70, but I bet that also means they won't restock them - at least not at $0.95. I'm sure I can find more. And if I can't, I'll break the hickey off the more expensive ones. It fits in nicely. I had to force it back out of the sample I assembled with some pliers. I thought I was going to break it pushing it out. I'll still glue it in somehow to make it secure, but it won't need any adapter and sits flush - so I'm super satisfied with that.
Here begins the bad news: The socket won't fit in any curved pipe. So arrangements like this are impossible - at least as shown. Extensions would be needed on the ends.
Also, the bulbs are expensive. I knew that going in, but I hoped that the candelabra base would be less expensive. MSRP from Bulbrite, which is what I am pretty sure I'll use at this point, is around $13.00 per bulb, depending on design. I went to one of bulbrite's Atlanta area retailers today, and they were willing to special order - even drop-ship - my small and custom order at a discount. Still, the order comes to more than $600. This would get me 65 bulbs - which is a lot. Follow me here...
It was suggested by a lighting designer at the retailer I visited
that I would want about 800W of incandescents to fully light my space (12x22 I told him) for cleaning and such. 800W means 32 bulbs (25W each). Since I've got 8 sconces, that works out to 4 bulbs per sconce pretty nicely. So 65 bulbs is a case of each of Bulbrite's 5 designs. 25 T6 bulbs, 10 AT15 bulbs with a "thread" filament, 10 AT15 bulbs with a "loop" filament, 10 ST15 bulbs with a "thread" filament, and 10 ST15 bulbs with a "spiral" filament. So that is one full set to install, one full set for back up, and one extra T6... If you want explanation of those designations, click here
and then hover with your mouse over the ordering codes that you can find at the bottom of the page in the technical specifications area.
Obviously, I don't have to order it that way, but I like the variety. It gives me enough design flexibility and design tools while still giving me a design box to work in. I lack creativity and vision when it comes to this sort of stuff, so having some rules like - 'use 5 AT15 bulbs with "thread" filaments somewhere in these 8 fixtures' gives me a problem to solve instead of a design to originate - I can work from within that box, so to speak.