Charlee,
I went to April 1930.com and looked up their Pinkers. No foot with them. The machine drives the tool by mounting to the presser foot shaft while the machine drives it.
http://www.april1930s.com/html/singe...ng_attach.html
Miriam,
I'm not sure at all. It does look like a Fagotting foot like previous poster said. The pics in the manual also on April 1930 matches to a T.
Joe