Yeah, looked at that too as the back edge of mine sits flat/flush with the lip that returns in behind that area so as to form the drain channel across the back of the rear screen. May have had a replacement box section but the rest of it (below) looks pretty original, or at least in the right place. If the original (if it was a complete ute body they used) was like that then it would be obvious why it rusted out as the water couldn't escape out of the sides (above the drain holes, should be a 2-5mm gap in the bottom of the box where it attaches) like it is supposed to. Just can't see where the drain holes should be in the front of the bed either. Would need to see it but for five grand it would still be a great buy I'd reckon, just don't have the moolah at the moment as it has just gone/going into my HJ resto.