Mary, I believe that Simanco was a type of material.  It probably
isn't a singer unless it has SINGER on it.  For a couple of years,
after Singer bought out Wheeler and Wilson, the Wheeler and Wilson was
on the Singer machine, but for all the other years, the name SINGER
was put on all makes and models that Singer put out.  A good web page
to look at about sewing machines is:
        http://www.icsi.net/~pickens/index.shtml

Check it out. It is very comprehensive and interesting.

Debra Westerman