With the door gap braced along its' length with a piece of angle iron I cut away the original outer and an old repaired inner sill. I then welded the strengthener sill to the outer sill that I got from Auto Craft, cleaned up any welds and trimmed any excess metal from the van and the panels that prevented a comfortable fit for all the parts.
Trying to get the sill aligned just right to the doors, current chassis and curve of the body took a lot of trial and error until I was happy with a position I liked. Although this meant the rear wheel arch patch I'd fitted earlier didn't match at the lower lip and had to be reworked to align. The outer sill was then tack welded, checked for alignment with the door gaps, their closed position and the outer curve of the van, and then finally the sill was welded in position. I worked out from the old floor that the top of the outer sill sits about 8 mm higher than the top of the chassis rails because of the step in the floor panel.
When fitting the inner sill I had to pull the sill into the center with rope (!) to get the outside bodyline straight and to reduce the gap between the sill and the chassis rails. Although I supported it with the angle iron it still bowed out at the rear cargo door hinge line. Unfortunately at the moment I'm not welding the inner sill to the current chassis as these pieces will be replaced later, so with the inner sill positioned correctly and just welded at either end I have to sort the gaps to the chassis again later.
