I doubt a decal came with the Columbia installation kit. Early 34 Columbia were called Dual Ratios not Two Speed. I believe the first Columbia sale ads were in 1934.
Many vendors carry the Columbia decal and I suspect it was the real deal to advertise their product. I put one on the wind wing of a '40 coupe that I once owned.
Back in the day there was a cast metal badge that you could bolt to your grille or front bumper. Auburn cars in the 1930s had a Columbia rear axle as a standard fitting with the controls in the center of the steering wheel. Regards, Kevin.