Acrylic Scales

Question from a true amatuer.
I have a set of acrylic scales cut out of a flat 1/8" sheet
I want to shape the scales by rounding off the edges.
I have all sorts of sandpaper sheets and I also have a dremel
with sanding discs and even a power drill if it would be of use.

What is the best way way to work on these scales to shape them?

fine file or hand sanding , use water or WD-40 to avoid all the fine dust that will come off.
Power tools are not desirable on Acrylic because it melts at pretty low temperatures.

Hand sanding is the best way to shape Acrylic scales. I usually fold my paper 3-4 times to stiffen it up so I have a firm edge to work with. If your wanting a rounder edge the single layer paper with your finger tips work great.
As mentioned above, power tools will melt it to quickly and/or rip up to much material to fast. Wet sanding does help the dust and it will also give you a great polished edge depending on the grit paper used. I will wet sand to 1500 and it comes out sweet.

I use a router on the edges of the scales that I make out of Corian (basically acrylic). I think it is the quickest method and it gives consistent results. Almost exclusively, I use a 45 degree bit for a nice bevelled edge. But round-over bits should give you a nice curved edge.

There is a router/shaper table for dremmels. I've never used it so I can't recommend it one way or the other.