Leon,
Necchis are notorious for being seized up with old gunk even when they were taken care of in a previous life. There's a very good tutorial in the files of the Yahoo group Vintage Necchis on cleaning and unfreezing them and she used a Supernova as an example machine. Rubbing alcohol is a great cleaner/degunker for the innards of these machines. After reading this tute years ago, 90% rubbing alcohol went into my arsenal and it's what I use to clean the innards of any gunky machine I get now.
Cari