Intra-Matic

Register placement follows the caliber and is a quick sanity check

The 7753's registers sit horizontally opposed rather than in the 7750's tri-compax arrangement. A watch presented as an Intra-Matic Auto Chrono with three registers, or with registers in the 7750 positions, is either a different reference or is not carrying the caliber claimed for it.

H-31 is a Valjoux 7753 and should look like one

The H designation is a Hamilton label, not a claim of in-house origin. Expect 7753 architecture: cam-switched chronograph, oscillating-pinion clutch, unidirectional rotor with the characteristic slight wobble, and a 60-hour reserve obtained from a revised barrel. A movement that does not present 7750-family architecture is not an H-31, whatever the rotor says.