Honestly this elevator is 44 years and it is near the end of its life even if you get it fixed you should probably start budgeting for a modernization. Sounds like you’ve already wasted $6k and your elevator isn’t anymore reliable. You have to understand stuff wears out the mechanical tolerances change and it will never operate like new. I bet you don’t drive a 44yr old car to work everyday. It’s only going to become more costly and time consuming sourcing parts and keeping that elevator going. I’m sure it’s not what you want to hear but I don’t think your elevator company is steering you wrong. Just my 2 cents.