New to me Pfaff 1221-part 2
 

So finally wiggled the bobbin case out. For such a pristine (otherwise) machine, it was rusted in place or some such! So how do I clean it now?

I wouldn't even attempt to clean the bobbin case. New ones are available. Cleaning up the hook assembly will be necessary. Them bobbin cases are really close fitting in the hook. E-bay has some 1221 parts but could not find any hook assemblies.

wow that is ugly. yes, replace it.

Thanks! So I already have another bobbin case. And I can try to clean this one and it won't matter if it doesn't work.

Give it a good soak in Evaporust for a couple of hours, then polish with Maas, Peeks or other favorite metal polish. Now that you have another, what could it hurt?

My thought exactly...