I just had a poke around at that right side and there is a white washer there, it's just been painted over at some point with black paint, which is why the metal looks so thick. There's absolutely no play in the hinge but I'll book it in at some point.
Thanks for your help chap, seems like I have quite the shopping list:
longer seatpost
hinge service
frame catch
easy wheels
front luggage block
luggage
I just had a poke around at that right side and there is a white washer there, it's just been painted over at some point with black paint, which is why the metal looks so thick. There's absolutely no play in the hinge but I'll book it in at some point.