getting some welding done on the van and what to mount some rear seatblets for the rock & roll bed... for people, but predominantly for a child. I'm hoping someone has done it before to what I assume is a converted panel van. I've looked at the Wiki but it isn't clear. My seatbelts are the Securon 3-point inertia type that JK sell.
here's the instruction leaflet, showing a mounted reel in the rear of the vehicle (looking forwards from the engine bay at the near side of the vehicle)

I have an LHD camper, so that side is taken up with cupboards etc. Here's a picture of the inner off side of the rear where the right hand end of the seat goes. The sliding door is on the left of the picture. I have put arrows in my picture (below) to show where I am assuming I should put the chassis mounts. At the bottom of the picture you can see the lap belt that in the central position on the R & R bed. I haven't double checked to see if there's a mounting point near the arrow for the lower mounting point, but if there isn't one I am assuming I should have one welded in around there.

My questions are...
1 Is this the best place to mount the upper stirrup for comfort and safety ? Would it not be better further forward, either under the window hole or on a bar in where the window would be ?
2 Has anyone got a similar picture with a seatbelt installed ?
3 I am assuming that the reel is mounted inside the rear wheel arch panel, as in the diagram below, does the mount need to be more than the 1 bolt supplied ? In the picture below, it is reinforced with three bolts (got this picture from somewhere else)
Here is a diagram of the installed belt, looking back at the near side of the van from the rear. I'd also like to get hold of the trim piece marked 4 in the 2nd picture

hoping someone can help
tia
Stefvan