Nice example of old quality Windy.
Engine Turning seems to add an appearance of quality to many items.
I also agree that it serves to preserve a surface better. I did some random E/turning on the Throttle Plate I made for an old Carburettor I rebuilt before 'Bluing' and quenching in Oil. Certainly renders it resistant to corrosion and looks nice….even though it is out of sight.

Regards