This is the Master Airscrew Razor Plane from Windsor Propeller Company.
FEATURES: Engineered to use a special .017" x 1-3/4" blade. The cutting depth can be set accurately and rigidly. For balsa wood. It rounds and smoothes the contours of cowlings and fuselages, shapes edges and thins strips. It uses a heavy duty industrial grade cutting blade. Blade is replaceable. It's unconditionally guaranteed for a period of 5 years.
INCLUDES: One Razor Plane
REQUIRES: For Storage: lightly oil blade
SPECS: Size: 3" x 2"
COMMENTS: Some experimentation may be necessary to learn the cutting technique used by experienced craftsmen.