Before JAA came along 'Brown' licences were for life.
With the exception of a couple of years (which has caught many out) the UK PPL whether brown or not was indeed for life but the OP holds a UK JAA compliant licence.
Obtaining a French licence will be possible as long as you speak French which is why for most Ireland is particularly attractive. The French will also require that you undertake an expensive EASA English Language Assessment (normally in Paris) - although you are English you are not given credit.