Thanks to help from mpexus pointing me to an advert on the Portuguese version of Gumtree/CL, I got in contact with a really nice guy in Portugal, who had a fantastically well looked after P4. After a lot of emails, and a lot of both of us being messed around by couriers and the banks, this finally arrived on Monday. I'm over the moon with it! The fretboard is quite light in colour for one of these, but I like it. Has a bit of figure, and looks pretty.
Plays amazing, and sounds fantastic, just like the others. Here's a rough video of a really cool bit of picking from Pull Me Under (Petrucci never plays this live, but it's so cool, well worth tackling to work on your alternate picking across strings). I'll do something proper with it once I've got my chops back up to speed (I've not been playing for 3 months).