there are tell tale signs which many of us observe for the clock.
the diameter of the clock is a first indication.
the knobs on the back of the clock are a sure indication of whether it is 240 or 190. a 240 movement have smaller knobs and mounting screw. the back case is mounted on with 3 small screws.
the stem wind crown is slightly different design between a 240 and 190, even the clock hands are slightly different design if you observe closer the minute hand.
examples of non 240 clocks.
https://www.ebay.com/itm/Vintage-Angelu ... SwiR5dBE3g
https://www.ebay.com/itm/Vintage-Swiss- ... 7203!US!-1
https://www.ebay.com/itm/Rare-ANGELUS-M ... SwnhVc6JXJ
https://www.ebay.com/itm/Very-Rare-ANGE ... SwhIZbIoGd