Yeah, the vibration basically disappeared after refitting standard mounts.
I took the Collins ones off and refitted them a couple of times although I can't see how it would be possible to fit them wrongly with the longer threads at one end.
The extra harshness from the Collins mounts was probably something I would have lived with 20 years ago but the car drove so well before, it seemed a shame to change it.
Oh well
Pic of the car in case anyone is interested sometimes use it for the school run, my wee girl loves it