Since it turns all you have to do is paint on the kerosene with a brush - you should not have to dis-assemble everything to get it working just fine. I got one that was frozen up with dried up oil working by just only dotting Triflow on the moving parts. You might want to dis-assemble a bobbin area - clean and re-assemble. Then go on and clean dried up oil with Gojo. Chrome cleaner or Barkeeper's friend will clean rust off chrome. The tension can usually be cleaned by flossing that area with a string and a bit of oil. You only need to completely dis-assemble if you are planning to repaint or it is totally rusted up. check out Muv and Fav's videos Thread: HOW TO CLEAN UP and use a vintage sewing machine - videos by Muv and Fav
http://www.quiltingboard.com/vintage...v-t167789.html - I have a Singer 319 I cleaned without a lot of dis-assembly - it was pretty dirty too. Singer 319 in need of TLC
http://www.quiltingboard.com/picture...c-t162425.html and a Japanese 15 I cleaned up without dis-assembly. Janie Doe, the 15 Clone - make over -
http://www.quiltingboard.com/vintage...r-t169127.html that one took about an hour - what a transformation - Janie went from not moving to moving freely. We did not get her completly clean at this time. We just got her working and her surface cleaned. Hannah was there and she is very pregnant - we did not want to use a lot of chemicals. The machine will need to be cleaned in the spring when we can work out doors.
I have a treadle that would barely move. It was loaded up with thread. Got that out then I got some triflow grease on the moving parts and she rocks great now.