Basically it depends on the shape, money you got, time and tools available. Screwing into is quite difficult. I think its because when you drill it heats up and you can see it go frosty, I think its called crystallisation. That makes it go extremely hard, when I was screwing in it made all weird noises like screeches also a couple of screws sheared off at the head ( nightmare to get out ). I found that use the closest drill bit you can find and if you have too much trouble use the next one up, I did that with the next bolts and it still grabed really well.
The thickest arcylic I could find was 38mm. I didn't allow for the switch selector so I ended up having the route more out and as a consequence there is a small rectangle on the back about 20mmx40mm that is less then 1mm from the outside edge ( no joke, its pretty crazy ). So just make sure your design is spot on, its expensive stuff you'll be playing with.
I didn't tap it but for the bridge ( schaller roller bridge, sits ont top - strings go through the back of it! ) I used this cutting fluid that kind of made the screws self tapping. Sheets are very expensive, I live in Australia and to get a sheet ( 1.5mx3m ) is around $2000 (dont quote me on prices ). I got it cut with computer driven router. I had to draw very precise drawings on CAD, especially of the neck joint as 1mm at the joint is 10-15mm at the top. But making a mould is a very good idea.
Thanks, me too
P.S ill take some more pics if you want to see an area close up or the back or what not!!!!