Rusted coolant lines

[Bosworth Audio]

About a month ago I noticed that my car was pissing coolant from under the plenum, but since i rarely ever drive it anymore since there is so much done to it, it sat for about a month while Infiniti of Lake Norman sourced every hose, gasket, o-ring etc that could possible be changed while i had the intake manifold off. I finally got to pulling everything off yesterday, replaced everything, bolted it all back together and found the leak was even larger than before. As soon as i hit the started coolant started flooding out the back of the engine. got it back up on a lift and noticed it was the metal hardlines behind the engine that were leaking. I pulled it all back apart and took every steel hardline out to examine them and every one is rusted completely. has anyone else had this issue?

My solution? I bent up new stainless lines where they were needed, deleted the coolant line completely going to the throttle body spacer as they're primarily used for up north to prevent icing of some sort, tig welded the hole shut on the aluminum crossover tube that went to the throttle body, re-routed the heater core lines to delete the steel pipes and am about to put it back together again. while I was at it, deleted and rerouted most of the vacuum lines to clean up most of the mess that is on the front side of the engine to underneath the intake plenum just to have a cleaner engine bay.