Alasdair,
Having been through selling a Defender would also recommend Pistonheads as well.
If you are an early member then its free but obviously new members will have to pay.
Also try defender2.net, LRO, Land Rover monthly and Landyzone (if you have enough posts)
For info mentioned it to someone looking at mine but obviously their was a big difference in price. It looks fantastic and with all the work you have done its a much better longer term proposition to anyone wanting to buy a Defender.
George