Good evening chaps. Can anyone help me identify which reference Speedmaster a C.321 with serial number 24.014.*** most likely fits in with - or if it's possibly not even from a Speedy?
I know it's likely either a 105.003-65 or 105.012-65 so if you have seen this serial range in either I'd like to hear.
Many thanks.

 

That number dates to late 1966 production. You have already identified which models are the most likely candidates, but even if it is a Speedy movement (which is not guaranteed as other models used the 321) it is not really possible to say whether a given serial put into an Ed White or Pro. There are tables of serial blocks on the MWO website which will be worth a look but I don't think you will find anything definitive.