The parcel shelves will need sorting as I want them to extend to the upright so I can secure them. The shelf on the drivers side is 5mm short while the one on the passenger side is 3mm short. The shelves are no longer available and mine are a bit rough. I currently have a company who make replacement panels for all sorts of old cars trying to make me two new shelves.
As they were all built, they all had a gap here, that was so that regardless of body build tolerances, the Trays would fit. To make up the difference here, there's a screw that went through from the Side Screen Steady Bar, through the Body and then picked up the Tray, in that gap, they fitted washers ' PWZ104 ' with a quantity being described as ' A/R ' (As Required). PWZ is a Plain Zinc Plated Flat Washer and the 104 is a Standard 1/4" size.
All the same, I agree with your thinking here Martin, the gap is ugly and packing them out with Washers, while it maybe 'factory' it looks like a Chewing-gum 'fix'. I make my trays to fit too.