I don’t know if they can do it but you might try Myron Toback in
NYC. They have a good selection of tubing and also do special
orders. I would guess this would have to be a special order
situation. I just special ordered some 18k square tubing from them.
They had a substantial minimum order of 25 dwt. in gold.
Most of the dealers like Hoover and Strong and Hauser and Miller
don’t make their own tubing. They buy it from Stern Leach in
Attleboro, Mass. You might try them, but the minimums will be very
large.
Fine silver may be a problem since it is so soft. I know I tried to
get some mill products in 22K gold and they said it was too soft and
sticky to work with to make odder forms of wire or tubing.
Good luck with your hunt.
Don Friedlich