Always better late than never
If it were mine I would make sure it does not have any leaks, replace the compressor and the dryer, flush everything out, vacuum and charge with r12 til the site glass cleared. The site that has helped me the most is www.ackits.com.
I would start by reading all I could get my hands on about it if I were you.
You can always come here and ask questions but try the search first. Lot's of info on these systems. Be glad you have the 240D
versus the 300D model