I've pics of them as: hand cranks, treadle, and electric motor machines. The electric motor versions are set up with the same identical Alpha Sew parts Sew-Classic sells.
They are current manufacture and definitely not antiques. They are not even vintage.
Here is a link to Singer India showing these machines: {
http://www.singerindia.net/Straight_Stich.aspx?id=1 }
I'd like to have one for my collection someday. They are very pretty.
Joe