Consider the cost of a replacement part for the undercarriage of an obselete aircraft.
It is going to be EXPENSIVE for very good reasons, the undercarriage will have been manufactured by an outside contractor 30+ years ago. The drawings and tooling may still exist but all calibration certificates will be expired and the last man who actually made one will have retired. Materials need to be sourced and ordered, when eveything is organised they now have to stop a production line, set it up for a single part, QA the the part, reset the production line to normal work and explain why their normal production is now days behind schedule.
Serious hassle.so someone has to pay and then everyone who handles it on the way to the customer has to add their margin.
This is NOT going to be cheap.