The campsite went into administration and was temporarily run by the council. There was camping available last year and according to the Event Details, is still available this year:
http://www.angus.gov.uk/southlinksholidaypark

Thanks Louise.. . Missed that bit.

Turns out 1 of my 3- his parents live in Hillside so we will crash there. (I knew they did and was hoping he'd offer 😉)

Cheers though.