Pam says: looks like the one on my mom's Singer that I learned to sew on, I think that it's a 404? If so, the cams could be from that machine, too -- her machine had cams for various fancy stitches.
Debi Dee (dinglebiddy at hotmail.com) says: This looks like the throat plate on my Singer 338, purchased by my grandmother in the late 1960's. There are two throat plates for this machine, one with a wide slot for zigzag and specialty stitches, and one witha small round hole meant only for straight stitches.
Lin n Maine (lin-b at webtv.net) says: The throat plate seems to be the same as my straight stitch 348 Style Mate.
Tom File (tafile at highstream.net) writes: It looks like my throat plate on my singer 348 I bought new in 1967.
Helene (helene26 at bellsouth.net) writes: It looks like my singer 248 fashionmate. This model also takes the flat cams. Hope it helps. Helene