Singer #AD443078 is a Mdl 99, one of 5,000 allotted 1-6-32.
The Singer 99s needle fits flat to the right and threads left to right, just the opposite of the Featherweights.
Manuals can be had here:
http://www.singerco.com/accessories/instruction-manuals
They are free .pdf downloads.
The Singer 99 is almost identical to the 66s except it's a 3/4 size machine rather than a full sized one.
Joe