I keep all my documents with me in china,except for word processing certificate I got when I was on the dole and which I now lost. Birth cert not really needed in China, but I do have it. Lung xrays seem a bit overkill, especially as it is all digital machines now?

Smart move, San Migs- if you do meet that future Mrs Migs and want to cart her back to England, the British will want to see your birth certificate.