Thanks to all who helped me figure out what was what. I 'borrowed' the treadle belt from Mrs Willard to check it out, and now see how the derailer/wheel flange work. Also, thanks for helping me ID the feet. I'd never seen a binding foot with the posts before-I wonder what function they serve? Now I'm on the hunt for how to use the feet. I did find a conversion kit for the presser bar on eBay, once I figured out what to call it.
I am *determined* to learn to use this competently! Mrs Willard is a lovely old gal, but the boat shuttle is causing me no end of headaches! I hope this, being more like what I'm already familiar with, goes more smoothly.