Right, here it is:
It is missing a chain.
Bloody hell! Look at the negative bb drop on that! No offence Baz, but that's what I call a personal build, which usually doesn't add up to the selling price you'd like. It's a 1998 Ground Control Extreme frame, designed for 4" of travel front and rear and you've casually dosed it up to 8". I'm not saying it doesn't work, I wouldn't know, may well be it does, but my guess is that most people who might want those forks don't want a 1998 frame. And vice versa.
Looks to me like a classic case of sell it part by part, or get half as much or less if you sell it as a complete bike.
I'd guess you might get £200 for the Boxxer on eBay if in good condition and not needing a service, depending what model it is, the wheels might raise £80-100, the frame not much even though it's looking quite smart - depends on the condition of the shock/bushes/when serviced, but less than £100, the disc brake I don't know but must be £50+, and the other bits would all chip in with useful bits of money if sold separately.
And this isn't a good time of year to be selling incidentally!