sewing machine advice-singer?

There's a visual guide to identifying old singer sewing machines from craigslist photos, for just this purpose:

http://www.singersewinginfo.co.uk/gallery_machines/

Once you figure out the model numbers you could post them here/look them up.

can't go wrong for $20?

take some nylon fabric and try sewing it to see if they work

I have a machine like the one on the lower picture. It's very old but works very well en is pretty strong. I think older machines are more heavy duty and more durable than newer machines. More steel, less plastic. After a service it should work like a charm.
Good luck.

Niek

I would take them both. You will find some parts will be interchangeable. (Like the friction roller for the bobbin winder. These did not change with Singers for several years. One of the newer electric ones actually fit on the old foot/treadle ones.)

Take 'em both. Great price. Keep the one you like best, and sell the other for $20 or if you like them equally well, keep the oldest. Older is better with Singers. Still have my mom's 1947 Singer Flyweight, great machine.