Lawrence DeLuxe Slide Rule Lawrence Engineering Service Peru, Indiana

Vintage Engineering Instruments 250-V Slide Rule Peru Indiana

Vintage 10 Inch Slide Rule Engineering Instruments - Model 250 BT Peru Indiana

Vintage Lawrence Engineering Service Peru Indiana Slide Rule 10-B Wood USA

Vintage 10 Inch Slide Rule Engineering Instruments - Model 250 BT Peru Indiana

Lawrence Engineering Service Slide Rule Peru Indiana

Vintage Lawrence Engineering Service Peru Indiana Slide Rule 250-BT (Slide #705)

Vintage Engineering Instruments Wooden Slide Rule Peru Indiana USA