Designing a Digital Drill Gauge

I have started off with a stock design of a Tube which has a circumference of 100mm.

I now need to add in the holes which will measure the size of a drill bit so that we know what size of drill bit we are using. The holes sizes are 3mm, 4mm, 5mm, 5.5mm, 6mm, 6.8mm, 8mm, and 10mm.

I now need to add the size indicators which show what size each hole is so that we know what size of drill bit we are using.

Now I am going to customize my design to make it more like a C for the first letter of my name.

This is what it looks like after I group each different part together to create the final piece.

I have now finished my design and now need to know if you guys think I could change anything to make it better or look different.