- Upper Scale (430)
- Crown:
- "MADE IN ENGLAND"
- Top:
- "PATENT No. 183723"
- Bottom:
- "SCALE No. 430"
"OTIS KING'S POCKET CALCULATOR"
- Lower Scale (429)
- Top:
- "PATENTEES & SOLE MANUFACTURERS; CARBIC LTD,
51 HOLBORN VIADUCT, LONDON E.C.1
SCALE No 429 COPYRIGHT" - Bottom:
- "OTIS KING'S PATENT No. 183723"
