To fit the latches, drill the wagon side with 0.6mm dia hole. This hole is the same distance from the hinge line of the door as the opposite edge of door leaf, and at the same height as the hinge for internally braced doors. Study photographs for externally braced doors. (never shown on drawings).
Trim the etching, and file the tails smooth. Fold the latch back on back on itself, making sure that you open out the etched links between the two halves, and fit the latch into the hole with superglue, make sure the hook is pointing downwards. Â If you still have access available within the van, a blob of epoxy glue might be neater.