That bike looks superb mate, bit confused over the chair on it though as that one is different to what they should have come with. I assume it was just built for that test ride and the ones out of the factory would have been the standard one.
Yeah it'll be one of those "changeover" things again Andy - they probably hadn't moved to the viscount areo seat at the time of the test and release of the bike and possibly ran with the old MX seat for a short while before turning to the aero across the range by the time the catalogue was released
I'd go with the catalogue pic / aero seat for your build mate if it was me
And stop using the word "chair" FFS !