I luckily found an example of the Grigorovich I-Z vac kit from Kayuk. The accompanying 3-view from the instructions is below, and it conforms closely to the kit's outlines:
However, almost all other 3-views I've found of the I-Z show a considerably narrower chord. Here's an example:
Anyone know which is right? Or even closer? Photos of the I-Z aren't thick on the ground, and none that I've come across lead me to any conclusion about this wing chord mystery. Thanks for any help or advice!
Cheers,
Herb