can anyone tell me what other ignitions will swap into my 74 MX125?  the stator plate is cracked, and rusted and im sure on its last leg.  can i just toss a complete ignition off of a later yz125 on there?  what other bikes can i interchange with?

i think so but not sure

just about any thing can be put on it with a bit of machining and as long as it fits under the cover.

I don't have an answer as to what will fit but I would start looking for bikes that had similar engine architecture i.e. used same crankcases, crankshafts, etc..  One thing to be careful with whatever ignition you end up using is to set the timing based on distance BTDC, don't rely on factory timing marks for ignitions from different years and/or models. Is it possible to have your stator repaired or to find a good used part?  Good Luck!