Miriam, The feed dogs do drop via a lever on the bed underneath the bobbin winding mechanism.
to all, I agree the bobbin holder looks different than others I've seen.
Nancy, I agree it is not a 15 but it's like they somehow married a 99 and a 15 together with some features from each.
Am thinking of emailing the ISMACS digest along with pictures about this to see if some from across the pond have more information about this machine. It may be that someone over there has one or has the information.