It shows on the analogue meter that it is 1000/min.
507m ~ 1660 feet, which is about where the needle is.
So safe to assume that the analogue meter is in x1000 feet per minute.
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The dial has the text "100 / MIN", but I think you are right. If it were to read "1000 ft/min" all the read outs would be consistent with my observations.