LASORS 2003 is incorrect. The CAA confirm that you do not need any additional qualification other than differences training in order to fly a Microlight aircraft on a JAR-FCL SEP Class Rating.
You can either believe me or ask the CAA themselves. But it was confirmed again this very afternoon.
The NPPL is however, a different matter. A new AIC (3/04) will soon be released regularising the incorrectly formulated requirements in the current ANO; however, all will be sorted in a second AIC after the NPPL Policy and Steering Group have agreed the requirements; we'll try to do that by the end of the year so that the correct ANO requirements will be in law by mid-04. Of that the CAA is as certain as they possibly can be.