Gaggia Classic - leaky steam valve

[JonEdwards]

Hi all...

Got a bit of a drip issue going on from the gland where the steam knob shaft enters the rest of the valve.

I'm slightly suprised to see (on whipping the top off) that the valve ISN'T user serviceable (Where I was expecting the gland nut to be, there's just a smooth domed surface).

So it looks like I need to replace the whole steam manifold. Any good suggestions as to where I can get parts from, plus a guide as to price?

Cheers,

Jon