What about this

problem: since 2 months I feel and hear rough road surfaces vibrating in my steering column, just behind the dash. There are no problems on smooth tarmac, but e.g. cobblestones or tiny potholes make a lot of noise. I feel no wear, the steering column bushes were renewed a few years ago, this year brake reaction bars are fitted, new disc brakes, etc. The kin pins, shocks (Koni's), front springs, incl rebound springs are just a few years old. The Morgan feels firmer as before, but the resonating feeling and noises are disturbing me badly. My agent replied me to check if he had some tools left behind, but that isn't the case, and should sound differently. Somebody has any suggestions? I thought maybe the unit with the steering column stalks is vibrating, but I don't know wether that's possible?!