Cleaning, Repairing and Servicing a 50mm f/1.4 AI

The 50mm f/1.4 AI and its optical formula was inheritted by its successor and beyond which meant it was in production from the late 70s to 2025 so this lens as an option comes with a well known optical performance and can be found a slightly lower cost than its succesor. The f/1.4 AI ran from 1977-1981 so servicing is a must, with my copy having sticky and unusable focus as well as being very dirty.