Apologies for the late arrival on this one!
Firstly, you should not have had to do any machining bodgery on the underside of the platter or any of the plastic supports under the turntable. If I had to guess, I'd say that the impact of being dropped has knocked the suspension out of kilter or possibly damaged one or more of the supports. Still, if it's working now, that's the main thing.
As to cartridges, I'd personally go with a re-build in Germany - I'm really not a fan of the looks or sound of the SoundSmith versions. In addition, I realise that the unit has sentimental value but do think carefully before spending this sort of money on it. The Beocenter 2200 was a largely Japanese product with very little B&O DNA in it apart from the turntable mechanism. The amplifier has built-in loudness compensation that cannot be turned off and it has none of the normal Link system connectivity. What I'm trying to politely say is that B&O made some of the best music centres out there but, sadly, this wasn't one of them!
Engineers: fixing problems you didn't know you had in ways you don't understand.