tweetee,
That's one Singer I've never seen before. I notice the trap door on top, does it use cams, and do you have any? My wife and I have a thing for cams..
Also there is a gal in Australia by the name of Cyndy Kitt who is pretty knowledgeable about old(er) Singers.
Here is her site: {
http://www.annebonnyslocker.com.au/ckp/a.main/index.htm }
She might be able to help.
Joe