Taking an inventory of fixes needed on old sewing machines

I like to do small repairs on my sewing machines. I like to figure out how they work and be able to explain to a repair shop what needs to be done if I take them in. Here is a video of me taking an inventory of what needs to be done on my old sewing machines.

My old workhorse sewing machines including Viking 6010, Brother VX 757, and Elna Supermatic.