My apologies if we're already discussed the proof marks of the Cashmore Bob.
The original proof is 1896-1904 (MAXm) for 1 1/4 oz. with bore '13' = .710" - .718".
Reproof 1954-1989 for 3 1/4 TONS = 9800 psi with bore now .729".
The arrow is the proof date code which I can not decipher. For some reason it was often stamped upside down from the other marks.

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And then there is this one - what could they have been thinking?!? wink
1888 12g J. Blanch with 2 3/4” chambers, reproved in 1999 (Crown over R) for CIP Service pressure 740 BAR = 10,733 psi; Maximum statistical individual pressure 850 BAR = 12,328 psi.

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