Ah, my mistake, read it as missing part instead of the bit which is missing partsErr, the knob looks fine to me, its the valve inside thats wrong!
took mine apart and photographed it, Just realised though, its a Unimount2, I think?!?! The valve in mine looks like this, if thats any help.
Really can't remember the difference, sorry!
Remember all that TinyTim business, the little tw@t is currently getting his behind tanned by Robbo, hope your mate forwarded all the details!
You guys did well, shame you got a man sent off and banned from future events, lol.