Had a look at it tonight and found that the frame that the hornpush is fixed to was loose. It seemed to be held by a large bolt at the 6o'clock position so, I thought I would tighten it. Got my socket set at it and got a half turn on it and then , you guessed it , it went all loose again..... bugger !

The bolt turned out to be only a 4mm thread, despite the large 3/4"" head, and it was threaded into an aluminium frame, also about 4mm thick.
I managed to recover the situation by using a bolt with a slightly larger thread and "make" a new thread, worked very welll. I found that even when it was all tightened up, the frame was still mooving, I had to add a large spring washer and, bingo, all tight again........

So watch out if you have a go at it, my new nickname is the human torque wrench.....
Regards
Kermit