Hi Rupert, thanks for the reminder. I've taken a look and I do have a top mast. The split in the top is about 50mm long but there's no rivet. It's been caused by the top plastic plug being hamered in I guess...
Oh and it's anodised black not silver. I can send a couple of pictures if you txt me your e mail address.
Regards
Tony
O7977 5I2673