Is that a Continental O-200A, or an earler 65hp or 85hp variant? 100hp in such a compact light wood and fabric package must make for decent performance. Very nicely detailed inside and out. Great photos.
There is a superficial similarity, but the two designs are unrelated. The Minicab was a scaled down SIPA S.90. The Culver was metal, and the Minicab is largely wood and fabric.
