I agree with Hamish and will quickly add this one is nothing to fiddle with, I hope none of us have a fault here. Thor, why has your wheel been loose for ages? Check the splines on the column and wheel, if either appear rounded, beware. A tight nut does not always mean a tight or safe wheel… if the splines slip or strip, massive understeer immediately follows.
I bought a new motolita leather rim a cople of years back. Beautiful piece of kit.
However, when the boss is placed on the steering column it could be described as a ‘rattle fit’ i.e. there is a wee bit of play, not much but a wee bit.
When I pull up the centre nut there is still a tiny bit of play. Pull it up a little more and the play disappears and everything is tight. No idea what the torque is but I used a ? inch square drive rachet.
20 lb.ft or thereabouts is the max I’d tighten the column nut to.
The wheel should be a good fit on the splines, the fit should be such that you should be able to drive with no nut on the column, if tightening the nut removes slack something is wrong. If there is any play then I would suggest you buy a new column or hub - except I think the columns are no longer available so a good secondhand one might be the only way for now.
Check that the cable “jumpers” are in place over the steering UJ and from the steering rack to the chasis. With out these there is not any path to ground for the horn to complete the circuit.