Vtg C-Thru Ruler Co Proportional Scale Circular Slide Rule PS 80 Round USA

Artist Drawing Tool Proportional Scale Divider Ruler Craft Drafting And Image**

Vtg C-Thru Ruler Co Proportional Scale Circular Slide Rule PS 80 Round USA

Proportional Scale Unbranded Vintage 6" Circular Drafting Graphic Design

Folding Parallel Rule C-Thru Ruler Company 1500 - 12 inches in Box

Vintage PS 69 Proportional Scale C-Thru Ruler Company Made in United States

The C-Thru Ruler Co. 15 inch Folding Parallel Rule. Made in USA