Hi all,  Because the soldering operation is relatively easy, and
not all that different from soldering plumbing, I have purchased
appropriate sized brass tubing, mitered the corners and made my own
elbows.

To hold the parts in place before soldering, I make up a wooden
fixture with holes at right angles, or strategically located nails
to keep the parts aligned.  Following soldering, I smooth off the
solder and polish the whole part so that it looks very professional.

Obviously this takes more time than getting a catalog item, if
available.  But if you just need an occasional one it can be done
rather quickly. Most recently, on my Duo-Art grand I had a deteriorated
pot metal elbow of medium size that I replaced with a comparable sized
elbow that I made.

Pat DeWitt
Ft. Wayne, Indiana