sell people what they want and not what you have in stock.
Sometimes it is genuinely helpful at others you are simply trying to make a sale at any cost. This really pi**ed me off as I am in Africa and sent my wife down to do the deal and still ended up on an international call trying to get to the bottom of the issue. Not at all happy with the experience.
You used to be so good, probably feel you have a monopoly of the secondhand Japanese spares market in London, so providing a good service is low on your priorities now.