Lawrence Slide Rule 250-BT 1940s Vintage Engineering Instrument

Lawrence Slide Rule 250-BT 1940’s Vintage Lawrence Engineering Service w/Box

Vintage 1940s Lawrence Engineering Service 250-BT Wood Slide Rule USA with Case

Vintage Lawrence Engineering Service 10-B Slide Rule, 1940s

Lawrence Slide Rule 250-BT 1940’s Vintage Lawrence Engineering Service

Vintage Lawrence Engineering Service Wooden Slide Rule w/leather case 250-BT

Slide Rule Lawrence Engineering Service Wood Slide Rule w/ Case USA Vintage

Vintage 1940s Lawrence Engineering Service 250-BT Wood Slide Rule USA with Case