The spring in the lower hose was needed on the assembly line to keep the hose from collapsing from the suction fill method employed there. It’s a common trailer park myth that it’s needed later - it won’t actually affect anything.
It’s common for 50 + year old radiators to be no good, the sediment inside the tubes keeps them from conducting heat well. Another very common thing is that someone has changed the temp sender and now the temperature reads higher than it actually is because the “new” thermister is simply incorrect. More here: https://cccforum.discoursehosting.net/t/pet-peeve-part-store-temp-sensors/12643/1