This is an interesting aeroplane Milton, completely unfamiliar with it, amazing you got this done so well given that they only ever built one. Looks a lot like the Lockheed Vega but with an inline engine. A great conversion by the way.
As to the wind marker these turned up at some airfields in the Hump scenery and I had never seen one before either until then, they were never used in Australia.
Thank you Sir
Yes, Robert Nebazar was trained by

ckheed and worked there a number of years before returning to CZ to design.
Here is some general data on the Avia 156:
The Avia 156 was a 1930s Czechoslovakian 6-passenger commercial transport for both mail and passengers designed by Robert Nebasář and built by Avia, the type performed well but only one was built.
Development
The Avia 156 was a single-engined high-wing cantilever monoplane that first flew in 1934.
Powered by a Hispano-Suiza 12Ydrs inline piston engine and had fixed tail wheel landing gear.
The Avia 156 performed well in test flights but only a prototype was built.
Specifications
General characteristics
• Crew: 2
• Capacity: 6
• Length: 10.55 m (34 ft 7 in)
• Wingspan: 15.10 m (49 ft 6 in)
• Wing area: 38 m2 (410 sq ft)
• Empty weight: 2,305 kg (5,082 lb)
• Max takeoff weight: 3,790 kg (8,356 lb)
• Powerplant: 1 × Hispano-Suiza 12Ydrs inline piston engine, 630 kW (850 hp)
Performance
• Maximum speed: 350 km/h (220 mph; 190 kn)
• Cruising speed: 330 km/h (210 mph; 180 kn)
• Range: 950 km (590 mi; 513 nmi)
• Service ceiling: 6,200 m (20,341 ft)