Neither 1-1/16" or 27 mm O.D. (or I.D. -- I don't know which you
mean) brass tube appears to exist from any of the usual suppliers
I would consult (Grainger, McMaster-Carr, AllMetals, etc.), so that
could be a problem.

However, if you can source the tube, the elbows are actually easy
and kind of fun to make.  Just saw the pipe with a miter saw at
a 45-degree angle (a carbide blade works fine).  Rotate one piece by
180 degrees to make the right angle and butt them together with the
point of the elbow pointing up so you can get at the whole seam with
the solder, heat up with a torch and solder the seam.

The solder will flow around the seam if all the pipe is hot enough.
I held the two pieces in clamps that were heavy enough so that things
didn't move while soldering on top of a Kevlar shield on my bench top.

I'd make a more elaborate jig if I had to do a lot of them, but
this worked fine for making 20 to 30 half-inch elbows.  They get
prettier as you get some practice and only take a minute or two each.

[Later:] Lewis Brass in upstate New York appears to stock 1-1/16"
O.D. tubing:  http://www.lewisbrass.com/tubing/round-brass-tubing/ 

Interestingly, they also appear to have the twisted hexagonal brass
tube as used on European carousels, an item I've not previously found
this side of the Atlantic despite a lot of hunting!

Cheers,
Roger Wiegand
Wayland, Massachusetts, USA
http://www.carouselorgan.com/