when pulling a shot i've started to hear / feel an almost grinding noise as i pull the lever handle down - the shot still appears fine but it does sound quite 'expensive'

any ideas?

Mine makes that sound too. I'm guessing the piston gaskets need replacing or at least a little lubricant. I'm going to tackle that sometime soon using the method at;

[/url]http://www.home-barista.com/levers/refeathering-peacock-pavoni-head-gasket-replacement-t70.html

I see you're in the UK so you might want to talk to Espresso Services about getting a seal kit or they can service it for you from what I understand. They're at:

[url]http://www.espressoservices.co.uk/la_pavoni_.html

Some of the HB sponsor sites can help too. Stefano's springs to mind. [/url]http://espressocare.com/Qstore/Qstore.cgi

Hope this helps,
Sam.

How stiff is the lever coming down? Going up? Does that change with the heat of the machine?

It could be the seals. The main way to tell is if it changes as the machine heats up (over multiple shots, even just the up to let water in and the down to press)

The other problem could be in the bushings that the lever rides on. They do get dirty and can wear out over time.

But you almost always can use a seal rebuild and there are excellent directions on this site. Go with that (unless you did it a month ago!) and then see where you are.