I took my Discovery for an MOT and it needed some welding on the underside of the main chassis rails, the holes in them were about a 1/4 wide and 3" long, I put a plate over them so that the holes were covered, and on the retest he said it was ok But it should have been seam welded, Does this mean I should have put a plate the width of the chassis and welded on the sides of the rail instead of underneath which in thinking about it would have been easier. What exactly is a SEAM WELD.