Suh-WEET! Looks like a great receiver, based on what I read in the books.
Take it easy on that bad boy. You might want to sub out the electrolytics in
the power supply before applying juice, or just do a complete recap (hint:
take notes) and then power up.

If you haven't already found it, here's a manual to download:

ftp://bama.sbc.edu/downloads/national/nc240cs/

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html