Lessons Learned from my first sewing machine restoration.
(1) Know what's next. It seems like at every step, I would finish it, and only then take thought for the next one. So I would have to wait for equipment or materials to be ordered and shipped, and then I could work on the next step. I'm sure that's a small part of the reason why it took so very long to make any progress on this refurbishment.
(2) Keep related things together. As I acquired new machines, I put them in a tray labelled with the serial number of the machine. As I removed parts, I put them in plastic zipper bags, usually with a note identifying what the contents were, and put the bags in the appropriate tray. This helped a lot when trying to find the screw that was needed to hold a part on.
(3) Know when to stop digging. When I got to the disassembly step that involved removing the Taper Pin holding in the Arm Shaft, I tried and tried to whack it loose, but it would not budge. Finally, I realized that I really didn't have to remove the Arm Shaft; I could simply mask over the few exposed parts and it wouldn't be in the way for painting. In fact, there was very little else that I could remove at that point that would not be easier to cover for painting rather than removing.
(4) Paint everything at the same time. When I started painting the main chassis, I had neglected to prepare the balance wheel and the parts of the bobbin winder assembly that needed painting. After completing the rest of the machine, I had to go back and re-paint these parts, instead of being done with painting.
(5) Know what not to paint. When putting back the slide plates, I discovered that my lovely paint job had filled in grooves that the plates slid into. In order to get them in place, I had to dig the paint out of the grooves, and when I did that I damaged the paint on the bed nearby. I could have saved a lot of time and headache by masking off that area from the start.
(6) Don't be afraid to fail. You can spend much more time not doing something than doing it, failing, and learning how not to do it wrong again. And you may learn something else useful when you fix what you did wrong.