I guess they were trying to save space? Had to cut a tiny strip off each rib with a 5X loupe and #11 blade, make a template then repeat  9 times. If you notice the 1/2" square spar so I had to shoot the gap free hand. Oh and ribs were a larger scale so had to put in overtime at the printers. Just wondering if this rib stack drawing thing was common back in the day.

MM

  I can't make out much detail of the plan but looks like an Air Trails plan?? Upstart maybe? This was pretty typical of the time period and on up into the 60's at least. You can just do the root and tip rib and stack sand the ribs. Or, if you notice, the curve of the top and bottom of the airfoil is pretty consistent, and you can draw a center line for each rib, mark off the leading and trailing edges at their proper thickness, and then connect the dots with a template of the curve or use a French curve that matches the airfoil. Each rib you draw can be checked against the plan pretty easy.
  Type at you later,
   Dan McEntee

I routinely stack sand ribs for tapered wings.

I hand cut the center and tip ribs from the templates. 

I cut enough ribs for two planes a time.  The templates are one-sided, so I flip them for the second sanding. 

Rib spacing can be varied to fit the ribs.

I use a bit of dope to keep the stacks straight. 

The "bolts" sections of DuBro 4/40 pushrod stock.

This was fairly common practice back in the day to prevent wasting space in magazine articles (Flying Models). For example, Charles Mackey's Crusader plan was not available full size but overall dimensions were shown on the plan (span, boom length etc.). Small parts including wing ribs were printed full size at the back of the magazine. This approach gave builders the ability to replicate the model without the extra cost of purchasing a full size plan.