Not sure if this will be of any assistance to Brian
http://www.scotland.gov.uk/Publications/1999/03/pan54It states:
"• time limits on enforcement action provide for two time limits within which any enforcement action must be started:
a. four years for unauthorised operational development and change of use to a single dwellinghouse after which it becomes lawful if no enforcement action is taken, beginning with the date on which the operations were substantially completed or the change to a single dwellinghouse occurred;
b.
ten years for all other development including change of use (other than to a single dwellinghouse) and breaches of condition, after which they become lawful if no enforcement action is started, beginning with the date on which the breach occurred (Section 124)."
Is it possible for Brian to prove that his caravan has been on site for more than ten years? Does he have invoices from the landowner? Or even utility bills or something similar?
On the serving of the notice it states that:
"• An Enforcement Notice must then be served on the owner and the occupier of the land to which it relates, and any other person with an interest in the land if the authority considers that interest to be materially affected by the notice.
• It is important to ensure that all appropriate people have been served and to ensure that the alleged breach of control is not immune from enforcement, as there are specific grounds of appeal in respect of both these matters."
I suggest a phone call to the local planning department, asking about rights to appeal where the enforcement notice has not been served on the occupier.
Good luck and I hope to see the caravan on my next trip home