Depends what vehicle, and ex MOD landy there's plenty of choice, an Sherman tank and you might be joining lots of forums and waiting for one to come up.
Things have changed recenlty in MOD disposal and prices are up, meaning the LRs are not the bargain they used to be.
But and internet search should bring up a list of half a dozen decent MOD disposal agents. the pronlem with Withams for one is that the stock still belongs to the MOD who name the price, unless it's been sold as part of a lot or by auction. A lot of the dealers are making their money on the bigger stuff these days too.