I agree. It is not a Singer 66-1 but is a Singer 66 dash something. It is also called the Red Eye for the red eye in the decals. Nice machine in great shape. You did really well to get that for free!
I have many vintage machines. I did have a 66 Red Eye but traded it away to learn how to wire machines. My favorites are Singer 301 and 401. I also like my Pfaff 130; I find it much more reliable than later Pfaffs. (And that's only the start of my collection!)
Cricket