Tonight I compared the latches from my soft top and the hard top.
Obviously the hard top latches have hardly ever been used, whereas the soft top has had a reasonable amount of use.
It is very clear the the joints in the soft top set are very worn so there is now an excessive gap between the safety latch and main lever.
So I have fitted the hard top latches to the soft top and will try and refurbish the worn set. Or I will have to buy a new set.
Not very good for a car with genuinely less than 20k miles.