Steering wheel and honker

If you remove the wheel airbag then you will need to disable the entire system. It is part of the mot that the srs warning light comes on and then extinguishes after a self diagnostic. I guess that if you have removed the wheel bag and converted the passenger bag into a cubby hole it is possible that the tester will accept that no srs system is in place and therefore the absence of a warning on the dashboard shouldn't be a problem. Inform your insurer too as disabled safety systems will definitely attract the attention of a loss adjuster in the event of a claim. Personally I wouldn't bother with a new wheel if it's a road car, though if it's being trailered to quarries etc then crack on and don't worry about it.