Nancy, You said "Cathy if anyone can find out if there was a chain stitch attachment for any of the models I own, it would be you!"
Boy, is that a high pedestal that you have just put on me. I am a collector and a mechanic, but not a great historian or researcher.
I did just finished searching the needlebar site and the Historical Trade Literature in the Smithsonian Collection with no results.
My personal knowledge of treadle and hand crank machines that convert by use of a "chain stitch spider" are some White Rotaries, some Domestic VS machines and some Standards (both Slims and Stouts). There are also some later (1970-80) Kenmores that convert and the infamous Singer Touch & Sew series. Maybe someone else can add to this info.
Cathy