1) Are you SURE it's the motor? It's pointless (and expensive) blindly changing parts.
2) Is there any visible scorching anywhere?
3) it's not the foot pedal that went bang is it? It might even be a duff cable, especially where it enters a plug or passes into a casing.
3) EXACTLY which "201" model is it? These may help:
4) Do a Guugle search for something like "singer 201 repair" - that will also throw up a lot of helpful videos.
If you DO try doing any work, make notes. DONT rely on memory!