Not a giggle, again, but this is a back clamping 66 with what appears to be a hinged straight stitch foot. I emailed the seller about it, thinking that maybe s/he fabbed the foot, but she didn't understand my question. I've never seen a hinged back clamp foot before. Singer stopped making the back clampers in 1922/23. I think the best view of the foot is the last picture.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=251361981528