I also believe you should change the dryer when you open the system, as many manufacturers mandate. With the age of the car, and the fact that the compressor just failed, it is cheap insurance. Maybe I am over simplifying it, but the desiccant removes liquids from the system, and compressors don't work on liquids. So why risk having liquids in the system on your expensive new compressor? Note I called it a NEW compressor. I have to echo Larry's post on this, and the flushing of the system. Here in Florida, I have seen too many rebuilt compressors replaced after only one season. Spend the extra bucks on a new one, take the time to flush it thoroughly and gain the peace of mind.
(We folks in the toasty climates worry about the a/c more, didja notice?)
My $.02 worth.
Enjoy the work, and good luck!
1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)