Amazing find. Cool trike. I found this on the net....
" 1872 to 1941
Founder: Pierre Gendron
Specialty: In 1872, Pierre Gendron made the first "Pioneer" vehicle in a small workshop in his home near Toledo, Ohio. The company was originally organized with the purpose of manufacturing wire wheels. By 1920, in addition to wire wheels, Gendron was making baby carriages, tot's push cabs, and doll vehicles. With the increasing popularity of bicycle riding, Gendron manufactured a complete line of bikes. In 1928, Gendron Wheel Company, now recognized as one of the leaders in juvenile pedal vehicles, added pressed-steel toy trucks to their "Pioneer" line" of toys, utilizing the trade name of "Sampson". Sampson trucks are easily distinguished from American's Giant and Toledo Metal Wheel's Bull Dog trucks by the unique shape of its redesigned hood and radiator. The hood was designed to follow a more conventional radiator shape than the previous Mack profile radiator used by the other manufacturers. Sampson's near rectangular decal, with the word "Sampson", is affixed to the sides of the various service beds and a small Sampson decal is located at the top of the radiator. All trucks, except the low end items, came equipped with hand-cranked noisemakers. In all likelihood, the American-National Company, after sharing the tooling for the trucks with Toledo Metal Wheel, sold the same tooling to Gendron in 1928. Gendron revised the design of the hood and radiator of the truck to give it a Gendron personality and continued to manufacture Sampson trucks until about 1930 or 1931.In all probability, Gendron's "Sampson" steel trucks and airplanes were victims of the depression. Gendron continued to produce juvenile pedal toys and outdoor gym equipment until the outbreak of WWII. "
So it sounds as if Gendron started the shift from Sampson steel trucks to just pedal toys in the early 30s. Which would tend me to believe that there were more produced starting early 30s. So the timeline sounds right. As for determining if it was indeed produced in 33, that might be tough. The best you can do is try to find other Gendron products(of known vintage) and compare. I don't think there's a registry for them.
I also found at that Gendron invented the wire spoke wheel. So I guess all us cyclists owe some sort of homage to Pierre for his wonderful invention.
What did you end up paying for it?(That is, if you don't mind me asking)