2000 Dodge Grand Caravan rear heater line leak

My wife’s 2000 Dodge Grand Caravan has steal heater lins that run down the fire wall then connect to a hose that then connect to an aluminum pipe that sends the coolant to a rear heater core. The steal pipes are rusting through frome the outside and one of them failed. As a temporary fix I cut the steal line to get to a better section and bought longer length of 5/8" heater hose. I looked for replacement parts to replace the steal lines but I have only found this listed on e-bay. Help! Should I spend the time replacing this or just keep the temporary repair?

If it’s working I’d leave it alone.