Vintage 1974 Penn State PSU Memorabilia Army ROTC Conversion Slide Rule - 70s

Vintage 1974 Army ROTC Metric Conversion Slide Chart

Vintage 1974 Paper Metric Conversion Slide Chart Army ROTC advertising NOS

Vintage Metric Master Promo Metric Conversion Slide Rule Chart

The Metric Converter Slide Ruler Conversion Chart Vintage INSTITUTIONAL SERVICES

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

1974 Perrygraf 3M METRIC MASTER Calculator Slide Rule Conversion Chart