With the plywood and spruce order I also received 1/4 inch and 1/2 inch ply as "protective wrapping" to protect the spruce and Okoume. So I decided to take a piece of the 1/4 inch ply and make a "wing template". Here I found an interesting "engineer thing" (oddity?) - perhaps every other place in the VP1 plans measurements are in fractions (fortunately in American Standard vs. Metric). However, on the wing the designer (Evans) uses 100's of an inch? So I go to the web and search for decimal conversion to fractions in 1/64ths. It wasn't until about a month later at Home Depot I found a 6" ruler calibrated in 100's for about $5. So I used my ruler and made a template for the wing ribs. After I bought my 100's ruler I checked and sanded any variations between my 64ths measurements and the 100ths.