John,
Sorry about the bit of ribbing, but unless you can laugh about it, sometimes you could cry.
But joking aside, what is the tubing for? Could the item be made from something a little easier to bend?
I do have some easy to make bender plans that can take up to 1/4", in fact up to say 3/8", it just depends if you have a milling cutter of exactly the right size of the material you want to bend, to cut the half round formers on the mill using a spindexer or RT.
You are quite welcome to have a copy.
John