Antique Hudson’s Computing Scale Engineer Pocket Calculator Pump Slide Rule

Halden Calculex various parts for spares see pictures

Halden Calculex with case and instructions

Vtg Odd Lot - Trigonometer / Engineering Tool & Case, Tin, Bulldog, Lufkin, Wood

Cooke Troughton & Simms Engineering Slide Rule Vintage Collectable

Vintage Castell Precision Slide Rule Novo - Duplex No 2/83, 62/82 #1

Rare, Inglis Engineers Slide-Rule & Ready Reckoner, Antique, Poor Cond'n (A1080)

Concise Circular Slide Ruler No 28 Japan w Cover Booklet