Hi Ila!
I hardly know anything about vintage machine's, but I picked up a Necchi BU Mira and they are apparently very picky about being oiled. Well mine had sat unused for 10 years but had worked up until then. The needle was in the down position and I couldn't turn the balance wheel at all. I started oiling it Friday, by evening I was able to turn the wheel enough to remove the needle. I added more oil and went beyond where the manual showed to oil it. The next day it was turning but still stiff. I oiled and turned wheel at the same time. Finally Sunday (think it was Sunday, might have been Monday) it was moving really easily!! I tried it with the motor and it worked for the first time, but after a minute of running it seized up and when I turned the wheel it was smooth then stiff. I let it sit over night and it did the same thing the next day. I decided to oil it one more time and today it worked!! I'd say clean it really well and then oil it and see what happens. But keeping checking back on it
