Andrew, Flower,
I can't think of a reason why a paper licence is needed at all. An online inquiry to the CAA would be a much cheaper and more reliable method of establishing a person's flying credentials.
After all the actual pilot's licence is an intangible permission to fly granted by state. I can imagine that, in the pre-computer age, a special piece of paper complete with signatures and rubber stamps, must have been a great way of showing that this licence existed. But these days a printed paper record of anything at all looks like a weak form of evidence. Anybody who wants to know whether I am licensed should be able to do so by asking the CAA directly, e.g. via their website. (The sort of people who would want to know are almost certainly in possession of a computer. )
Maybe I should write to the ICAO and JAA to point this out.