Not quite the same as line repairs but I remember back in the early sixties my business had an old type 332 telephone which was always on the blink. The local telephone engineer used to come and fiddle around with it periodically and I eventually discovered that his repairs depended largely on inserting match sticks in the mechanism. He would not replace it for some reason to do with either the paperwork involved or his budget. One day it was giving problems and an engineer on temporary placement turned up and immediately replaced the old instrument with a brand new, up to date type 706 which never gave me any further trouble. I reckon it would have been cheaper to replace it in the first place than the cost of the repeated engineer visits.