I am sorry, I would never put myself behind a steering wheel with the kind of fixture depicted. It might be that it feels rock solid here and now, but how would it be after some hours' driving - constantly exposing it to torsional forces, bump steer on an uneven road etc. And if one should have the bad luck of a crash, be thrown against the wheel or have the wheel coming against you, I believe the whole thing would collapse and make the steering wheel stem/boss a dangerous weapon. I cannot think this would pass a MOT, and for a reason. For measuring out a well made spacer - yes, but driving with it - absolutely not.
