Do you trust CLA numbers stamped on old shutters?

I pulled a 1960s leaf shutter apart yesterday, and the factory marks said it was set at 1/500. After cleaning and reassembling, my tester showed 1/320 tops. Is there a known batch of these where the stamps were just optimistic, or am I chasing a tolerance that never existed in the first place? I have three more waiting on the bench with the same numbers.

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sullivan.riley19d ago

and honestly that tracks with what I see on most of these old leaf shutters, the factory numbers were always a stretch even when they were fresh. I've had a 1950s Compur that claimed 1/500 but topped out around 1/250 after a full rebuild, and the marks on the barrel were clean and original. you're not chasing a tolerance, you're chasing a marketing department, so I'd just set all three to your tested speeds and move on.