Oh, thank you so much Capt Chris for sharing. As for the angle, this is the most important

I also like the instruction from Ruana, I added the scanned leaflet to the message. And after sharpening, sometimes a burr or a wire edge remains, here is a good way to remove it from 12.5 minutes
https://www.youtube.com/watch?v=8FqUL6slhtA&t=764
True, he does not say anything about the constant angle, but it is clear that he observes it

I use only stones lately, there are different, artificial abrasives and natural ones. For Randall, my favorites are Crystalon, India from Norton and Craftsman and Sintered Ruby by Gesswein for end sharpening