Now I reveal to you the full model:
Photo from Peter J. Vincents site: https://www.pjv101.net/
The VIMA lettering was found in a box of old decals I had come across a couple of years ago waiting on such a project to come up (unsure who produced them as the sheet did not come with any packaging). The re-release of the SEM T-van kit has allowed me to build a more accurate representation of this wagon with all the trimmings. It will now take it's spot in my collection of freight stock.