Robert,

I think most of the old Scientific kits had 3/16" or 1/4" wings that had been partially sanded to an airfoil shape. Later ones were flat but thick. Eventually 1/8" thick wings were used, probably as a further cost reduction to be competitive.

As an example, my Little Bipe plans show a Babe Bee engine and 1/8" wings. The first Little Bipe had thicker wings and showed a OK Cub (which is .049). There was no Babe Bee at that time.

I remember drilling holes in the firewall for my Space Bug Junior intake.

Here is a Fox FAI .049. I do not have the standard .049. Also here is a Gilbert .07 for those who have never seen them.

George