We would be happy to find (and assume that most of you are looking for the same machines)
We use Glenda Thomas famous books I and II for identification:
Dr. Hougs baby
and all these different toy treadle sewing machines
old colored Müller toy sewing machines
Modell 15 and 20
mistery toy sewing machines, like...
plate 2-550 and 2-551
American Gem with big wheel
plate 2-821, 2-823
and all the other uncountable toy sewing machines, which we do not even know of or the one your are thinking about to trade or to sell....