Seagull does not bother with offering "higher grade" movements receiving special treatment during assembly. Would they do so, these might certainly run at C.O.S.C. chronometer standards with the power reserve in the above mentioned range.
Short history:
The ST1901 movement is nearly identical to the Venus 175 - parts are interchangeable. But the movement is not a copy or clone. It actually is the Venus 175, because Seagull has purchased the tooling from Venus in the early 1960ies. Seagull did copy the tooling to be able to produce at 2 locations. Differences or improvements to the Venus 175 are the increased beat (the Venus only had 18000 bph) and an added incabloc style shock absorber.
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