This is an interesting "conumdrum" as it is the only combination I have seen as a Wrenn Collector, and have no reason to doubt its authenticity.

The Wagon is a late "Barnsley Main Colleries" LImited Edition, with White Lettering, but minus the "black highlights" that you gererally see on this Limited Edition Wagon Wrenn W5500.

There is no Certificate with the Wagon.

The Period 4 box is labelled one end, with a typed label in Red Ink - W5500 BARNSLEY COLLIERY LIMITED EDITION as shown in the photograph. The box interior is cream, which matches the reverse colour of the yellow cardboard insert. The label is the correct size and type face as used on the Non Limited version W5109, but in Red ink not Black.