I have pics of mine. It is a class 15 Singer clone. Attachments are easy to find and I use universal needles in mine and it works fine.
http://www.quiltingboard.com/t-65782-1.htm
There is not much history to be found on class 15 clones. The Japanese were not great on details. However, generic manuals are not to hard to find. Is yours a Dial-a-Matic like my avatar?