Wasn't there some aircraft of the pre-war era that used screws into the
rib-caps instead of stitching?

Aeronca 7AC, 11AC and Ercoupe are two that I've recovered that use screws.

it can be a fun job---a nice Summer evening, a drop light under the wing to
show up the holes in the ribs, An ice pick to punch the holes, a six pack of
beer------------

Cheers:

Paul
N1431A
KSDM