It's for a shuttle with a plastic long bobbin? I don't think they are easy to come by. I did a quick search, and got a couple of hits fir your machine all on
this page, the bobbin is listed as item no #32438, which I take as Singer part number. The one listed for the Singer Touch & Sew 67A3 is marked "no longer available", but the one below for a tiny talor machine has the same part number. Stuff turn up on fleabay and various places now and then, the game with these old toys is to identify what you need and keep an eye out.