All the above, plus: (1) in my experience it tends to become more brittle (and prone to cracking) with age, so be particularly careful as this is second-hand. (mind you, the stuff I discovered this on was much older than yours will be). (2) I have successfully profiled it on a milling machine but am not sure whether a router is OK as the cutting speed is faster - I would defer to others on this point, but suspect it's worth a try as long as you watch out for the heat (3) if you have rough edges then very judicious application of a heat gun will remove the sharpness, and make the edge clearer again, but don't overdo it as it will soften- perspex can be heat-formed very nicely. (4) in case you didn't know, you can stick pieces together with acetone.
