I'm working with an older fixture and most of the pipes are fused which has made it unwieldy. I'm a novice at plumbing as well.
I've attached a picture of the faucet plumbing. Valves still work fine so I'm not touching those, but the spout portion had an elbow and nipple attached that were horribly corroded and fused, so I had to cut it off of the nipple in the center (hanging down). This took off part of that nipple's threading but not all of it, about half is left, it's galvanized steel as far as I can tell.
How should I attach a new elbow and nipple to this piece? Since the nipple is tapered (I think) I can't just buy a new steel elbow and screw it on, but I'm not sure. I've looked into the possibility of using a dielectric union to attach to it and then use a copper piece to run out to the tub, is that feasible?
I'm short on ideas but I know there are a ton of solutions in the plumbing space I'm not aware of. Thanks for any help.