Anthony Baird, managing director of gold dealer Baird & Co, said the company could not deliver any Britannia coins until August because of lack of supply.In the meantime, get the other bullion coins and get them safely offshore. You won't need to pay CGT to the British government on these offshore coins once you ship out permanently to Thailand.
What's really awful, of course, is that you never make 'capital' on gold, so why the hell should you pay any tax. What is happening is that paper currency rubbish is devaluing against gold money, not the other way around.
Oh well. As long as the men who reserve the right to themselves to hold guns disagree with that, do what you safely can to avoid them stealing your wealth through inflation, taxation, and regulation.