Welcome, it looks like you have a Davis underfeed. I don't know where you might find a shuttle and bobbins for your machine. Hopefully, Jon will be along and able to tell you about the needle needed for your machine. Are there any numbers cast in the bottom of your machine? Also is there any letters other than the "Manhattan" on the head? I think the serial number may be on the front slide plate or possibly under the front slide plate. Those would probably help, although Jon can sometimes just look at the picture and tell.
Janey - Neat people never make the exciting discoveries I do.