Sanding shims on a belt sander - that's a creative solution. Haven't seen that one in the shop manuals yet
Speaking of shims, I'm getting ready to adjust the valves in my Triumph 885 cc triple. I have a special tool for the job, which makes it easier. I think I'll start that in a month or so, while our Michigan weather is still snowy. DOHC valve adjustments can be a pain compared to SOHC.