In my early days of Aprilia ownership, before the car had been worked up into a reliable daily driver, and I was just chasing endless deep-seated problems, I took the differential unit down to Harry's one evening so that he could help me to change the pinion thrust bearing and reset the meshing. After the usual preamble of washing cups and cleaning just the amount of the kitchen I felt consistent with keeping bacteria under control, we set to on the diff. unit, and after some hours' joint effort (and every minute of watching Harry was a lesson learned), I was ready to return to North London with a fully-overhauled unit.
Now for the difficulty of paying. "Well, the bearing was a rare early type, can't get them any more, so that's a fiver. What about £8 ?" I was glad someone had beaten some principles into me. "Harry, you cannot charge that little!" "Well, none of you young chaps have money"
I gave him £15 in spite of poverty and against protestations.