Hi Marv
Thank you for your interest. The lines are for reference and I could have done it the way you suggested. As you can appreciate, there is more than one to skin a cat.
I thought about doing the job firstly on the mill hence the spot drilling on the faces. There was an issue with that. As it had a flat bottom counter bore and I wanted a tight fit on the mating part I decided, it would be a lot easier to machine in the lathe.
Normally I use this method to centre square bar in the four-jaw chuck, so it is perfectly concentric to each stock face This method is so accurate every time so I used it for this operation and it came out spot on.
Thank you again and I hope I have answered your question
The Home Engineer