The tell on a Featherweight is the tip up bed and the tiny size. Here is a good pic with the bed tipped up:
https://class221.com/index.php/221-2...21-centennial/
Most pics you find will have the bed down and ready to sew.
BTW, all the machines you have shown so far look to be nice machines in decent condition. If you want a “placeholder” machine I think any of them would be a good one and the prices are good.