It appears to be what they call a Singer Fiddle Base machine. Do they have the top of the case? My DH says it is definitely a candidate for restoration (even though it may never be a museum quality piece). You might find out that some of this discoloration is not rust but old oxidized oil. $20 is amazingly cheap. Go for it.
Originally Posted by so-sew
You vintage singer loving people have created a monster! Every day I check craigslist for new treasures! Today I found a 1865 Singer that appears to be in pretty rough shape. The simple fact that it is soooooo old and still around makes it desirable to me. It looks like a spool "peg" is missing from the top of the machine, but other than that I think the exterior is intact. Rusty, chipped, and sad looking, but still proudly surviving generations of sewers. I can get the machine for $25.
What do you all suggest for this antique addict? Is this as rare as I believe it to be, or are they pretty common? Does it look to be in a condition that is unsalvageagle? Of course there are no accessories. What you see is what you get.