Something in common
I noticed right away the interesting foot control on the Featherweight and the Singer 301. There is a post on the right for your foot to rest on while tipping your foot for the speed control. It was particularly evident to me the other day when I missed the post, and hit the control and off the machine went.
I've done that with another machine in my life that has this feature. I've had people ask me what the right side post is. Having that foot rest post in absolutely essential! It makes me wonder who had the idea first.....
Here are pictures of the machines, and their foot controls. It's fun thinking about this stuff.