We sold our camper just before Christmas last year through caravancampingsales. It was on for at least a month (possibly two) without a bite, and then we had several people contact us within a week. Fortunately one of them purchased it.
I think Bird's recommendations are spot on. Great photos get people excited, especially if the trailer is in great condition as you say. As a purchaser, the thought of buying a full canvas trailer in this weather, then taking it home to open it up and pack it, would fill me full of dread. As a seller, just imagine if a tyre kicker turns up, you open up the camper to show them, it rains, they don't want it or you don't want to sell it for half price, then how do you get it dry to pack it up. I would take the ad down too, and wait until the sun starts to shine, hopefully early spring when the camping bug starts to bite.
Check your price against others for sale to see if you are fair in your pricing, but remember that advertisers are asking what they want to get, quite often not what is realistic.
Good luck selling, I do know the pain of waiting.
