In reply to the use of tri-flow on machines. Miriam has good luck with it but I prefer not to use anything with silicon on my machines. I very seldom use kerosene I use Blast buster and then once free use sewing machine oil or clock oil which is very nuch the same as fine sperm whale oil. I guess I am from the old school and use what is recomended. Tri-flow is a lubricant and was I don't think intended to unfreeze gummed up parts but hey if it works go for it. Be aware the silicon will build up also and become like glass. We would never use it in the Army on hig tech stuff. This is just my thought on the matter. It is a matter of choice. Miriam and I talk a little about this during her and Phil's visit here and this is the only thing we do different. Boy I wish I had her skill with these old machines she is good.