Thanks for posting this neat little attachment. I have two of the Greist ZigZagger attachments. I don't think I have seen the overcaster. Looks like the overcaster has stitches similar to a serger - and for a whole lot less $$.
Care to share some of your pictures and the resulting stitches? Also what do the three different side things do?
Janey - Neat people never make the exciting discoveries I do.