I was just given my grandmother's model 27 treadle and am cleaning and overhauling it. I bought a 66 this weekend. The lady was dumbfounded I was able to thread it up and stitch out on it before I paid for it.
I will let you know which I like better after they are both cleaned and tuned up.
Now, what am I going to do with the handkerchief I sewed up at the shop? ;-)