Hi John,
My 120 had the rattle as described above, a quick recon proved the culprit to be the very same.
However, it rattled only in cold weather, never warm or hot weather. I bought the spare clips and foam rubber, then used the rubber for another job and never got round to fixing it as it was warm weather again. That was winter 2017/18.
It rattled all winter of 2018/2019 as well, which is only 2 months here, and I’ll get round to it this winter if I can find some more foam rubber, which is a real challenge in itself - that’s if it starts again. Hasn’t done so far, so it might be another 12 months before I need to address the issue!
A bit of trouble shooting would go a long way to figuring out whether that’s your problem or not. I taped my phone to the inside of the engine bay and pressed record. Then went driving slowly on a quiet road, using the stop watch app of another phone to correlate the exact time the vibration started and finished.
Good luck! Sounds like a few of these machines have this problem so go ahead and solve it, then if it’s not the problem you’ll know it’s something else, and it will save you a job in the future anyway