Maybe it was previously fitted with BRBs Robbie?
There's plenty of clearance between bars and tyres on the Roadsters due to wheel offset.
With 4/4 wheels with 185/70s there's no clearance. The sidewall just touches the BRB. So ready for the first MOT, I've modified the bars by nipping them oval and slotting the hole at the lower end of the bars. That's just enough.
It's said that this contact is acceptable for Morgans but I didnt want that issue going forward.
The Plus 4 has A similar wheel offset to the 4/4 so just make sure that there's clearance on full lock. If it touches you'll get a braking effect on full lock as the sidewall touches the bar.
Of course the factory might be predrilling all chassis now!