It seemed superfluous.
All I can say is that it's not hard. I used jeweller's files, fine sandpaper and a dremel polishing wheel with jeweller's rouge.
If you're replacing the tube, get the face you put the tube in flattened behind the bezel.
Gen, gen, rep before work. See the visible metal between the CGs that should be hidden by the bezel?
Once I've had a lot more practice, I think I could easily get good at it. Here's my modded 1680.