Just checked two trucks - one with recent new springs from a road spring manufacturer, one ex Electricity Board.
New springs are FRONT - bolts and tube, REAR - just bolts. The rears are helper spring type and have additional clips with three bolts spanning both main and helper pack, as well as the two leaf outer clips.
Elec Board truck has all clips with a threaded hole one side, so bolts (all with tubes) thread in to clip without requiring bolt.
So I would suggest just a bolt without tube is adequate for MOT, or else the spring makers would not supply in this condition.