It looks like a 125" wheelbase Sandringham 6 built by Hotspur Motor Cars in the UK. They did series, stage 1 and Defender versions IIRC and were mainly geared towards things like heavy cherry pickers, tippers and other commercial uses. That one has been blinged out sadly.
They were 6X6 with a drive through diff on the middle axle although there is no diff between the rear two axles so scrubbing is an issue. THe suspension was fairly neat as one axle had 88 mounts and the other 109 mounts so that the two systems could overlap allowing the wheels to position that close together.
My favourite is still the Centaur halftrack.