whereas the 5327 has only no 6: the case being larger, the dial can and does include a 3 and a 9.
As for the 5740, I suspect that its dial aperture is quite smaller, the bezel being large, than the one of the 5327, which has a thin bezel.
So, for me, when you turn the watch, the only reference which is perfectly sized for the 240 caliber is the 3940.