Vintage Kelsey Hayes Co. Promo Metric Master Conversion Slide Chart from 1975

Vintage 1979 Metric Converter Slide Rule Chart Learning Research Inc. Woodbury

Vintage Metric Master W.G. Carroll & Co Promo Metric Conversion Slide Rule Chart

Vintage United States Air Force promotional metric conversion slide rule

Vintage U.S.–Metric Conversion Slide Chart – Engineer Tool – USA

Vintage Tube Forging Of Welding Fittings Conversion Chart Slide Rule Reference

Vintage 1979 Metric Converter Slide Rule Chart Learning Research Inc. Woodbury

1974 Perrygraf 3M METRIC MASTER Calculator Slide Rule Conversion Chart