McKeesport PA and Toledo OH.
USA
Airplane builder circa 1927-8. Eber H Van Valkenberg Aircraft Co began building a three seat monoplane with side-by-side seating in a rear cabin and a forward cockpit that could be open or enclosed. It was sold to Dr Leland E Phelps of Toledo c.1928, who rebuilt and expanded the plane as a four place cabin. It was never flown when called the Van Valkenberg. It was licensed as Phelps Monoplane #1 and also seen as Phelps Z-281.
All Aero 