I notice nearly all other vertical pull Briggs I see have 3.5hp labels on them, while my later magnetron model says 3hp, yet it's performance is adequate as far as I can tell, though I have only used it on a light lawn.
Maybe this motor came out as the regulators were clamping down back home.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!