The front fenders and hood will get stretched 12", and the fender flares should end up at around 17" wide each. That is according to the guy updating the build thread, one of the two owners.
That thing should look very clean when all is said and done if that guy's previous rigs are any indication.
The rims are stock unimog rims, widened and fitted with 8 lug centers. If I remember correctly that thing has Tacoma disc brakes F&R and the newer 8 lug spacing, E-brake is a T-case mounted Nissan Patrol unit. The hubs have been drilled for a tire inflation system that will be controlled from the cab. The 8 lug centers were chosen for future availability of wheels and for increased strength over the 6 lug 5,5" spacing that is also very common here and was considered.
Definitely the most interesting rig in a long time.