When Im faced with something like that I mock it up. If I was welding a pipe to a pie Id want to slip a sleeve inside both ends to overlap the joint. Lots safer & stronger & no one will even know theres a slug inside. Just tack it so it stays across the joint. Anyway,, get the pipe to slip inside & get some fat wire & maybe a piece of broomstick or dowel of some sort. Set the inner tubing in place, then plug it & drill the plug to hold the wire youre gonna use to build your mock up. I have a large collection of wire tripods that were used to hang wreaths on at funerals. Its not hard wire, bends okay but its stout enough to not deflect much under its own weight.
Scrounging is fun, take your time, enjoy the hunt,,You can try clothes hanger wire,, Just hafta get it straight before ya go tryin to make a shape..

You can Mock it up or you can Fock it up,, Ive done it both ways,,


When setting the plug in the sleeve, dont drill all the way thru it, leave it solid so the wire cant slip down too far & leave enough dowel poking up to be able to pull it,