This is the tail tidy I built for my classic (shown in the pics). It's 6061-T6 aluminum with stainless HW. All built in house.
To install it I cut off the existing support framing just rear of the bracket holding up the fender and used s custom jig I built to drill the three mounting holes in the fender.
I'm thinking of raising the plate up even higher (but not the fin bracket - I like that where it is). I was concerned about blocking the tail light and I liked following the lines of the fender. But there's room to swivel it up more and that would further show off the rear clearance.
We'll see, that's certainly an easy enough change.
I also know how I can incorporate the existing license plate light, but I may not bother.