Forgot to provide credit to the source of the info . . . as a local locksmith worked away in my yard on a neglected and broken door lock, he explained what should and shouldn't be done. Afterwards, he handed me the bill.
He did leave me a can of the graphite spray he used and told me never to use WD4? or similar sprays. Guess it follows a similar rule to that of the MB sunroof slide paste . . .