I used the bench seat exactly as it came out of the Commodore ute. I just drilled new holes in the floor where they needed to be (i think 2 of the front holes line straight up, been a while since i did it) and fitted 50mmx50mm 3mm anchor plates under the floor with captive nuts welded on them, job done. It's nearly exactly the same width as the original WB bench seat and lines up with the steering wheel perfectly. The L/H bucket seat is actually offset slightly on the Commodore bench to make room for the centre seat (i.e the seats are further apart than 2 buckets with a console in a Commodore, this is how they are from the factory). Honestly, it works perfectly and much more comfortable than the original WB bench and the middle seat acts as an armrest when not in use.
Hope that helps.