Similar Dutch Army water bowser, dated 1980, on Ebay, has different drawbar, this type of trailer not really of much interest to collectors, compared to a cargo trailer its only use is carrying water
https://www.ebay.co.uk/itm/Water-Bowser-Military-Trailer/273044621224?hash=item3f92ba47a8:g:djUAAOSwD39abaQe