Very rare recording plate used by movements makers, 19th century.
Brass plate scribed both sides and drilled for a going-barrel movement, the plate stamped 10. 34.5 mm diameter. Together with another brass plate bearing no maker's stamp, with which it came to me - not shown.
JD is probably John Doke, movement maker, Prescot.
Plates like these were used to record various different sizes and designs of rough watch movements that could be ordered from the manufacturers prior to being finished. Rough movements rarely survive, these caliper plates even less so.
A rare an important aspect of our horological past. Both in typically handled condition, but still clearly showing the markings, and one with red sealing wax from where it had been fixed.
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