Just a few tips thrown at you:
When you drill it, exit the blank sllllooooooowwwwwwllllllyyyyyy. If not the blank can shatter when the bit exits the other side. If using a press, you can put some waste wood below it, sometimes helps. I just go slooooowwwwwwlllllly.
I use a round nose scraper. Bare in mind, it's not the best tool but I've got a worse skew, so that's my only recourse right now. I tend to move the tool slowly enough that I can just tell that the acrylic is starting to soften from the tool's friction heat.
Make sure you round off the square edges slowly. Lots of chip outs can occur here. If you have a belt sander, go ahead and knock down the sharp corners with that.
Sanding in stepped grits is a must. Wood can hide if you miss a grit, but acrylic is unforgiving. Make sure to hit your main three grits before hitting with all your micromesh (which I use with water or CA accellerator as a lube).
If the blank is a light color, or sometimes even a dark, you may want to consider painting inside the drilled tubes or painting the brass tubes a dark color to hide their brassyness when the blank is so thin at the nib and finial that it becomes translucent.