Ricoh OD-151-D, Engineering Rule

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Country of manufacture: Japan,            Date of manufacture: ____
Overall length: 35.3 cm,          Width: 4.7 cm,           Weight: 128.8 gms
Materials: Celluloid laminate over bamboo, metal end braces, adjustable
Cursor: 3.2 X 5.9 X 1.2 cms; alll plastic, adjustable; lines = single line, front and back
Scales: 26, extensions on A, B, C, D
Front: LL1, LL2, LL3, DF [ CF, CIF, ST, CI, C ] D, LL3, LL2, LL1
Back: KI, K, AI, A [ B, S, T, CI, C ] D, Ldb, P, DI
Gauge Marks: [ π, 4π (1257), 1/2π (1592), 2π (628), C, e, 1/e, ρ'', ρ', ρ^o , 1291 ( Abbrev. 'I', on C/D scale, unknown), E (7749), v (4189) ]
Condition: C4-C5 (Minimal to Normal Signs of Use)
Came with: Original blue/white plastic case/box

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