Following a link from another forum and i came across this: Google Earth Community: UK WWII RAF Airfields It is a .KMZ file with place markers for UK HAA sites, Decoys and WW2 RAF airfields. Most of the placemarks are not exact but seem to be within 1/4 mile of the actual site.
Great link penance. I've enjoyed looking at the sound mirrors - especially the one on Malta. Still a few glitches on some of the links but I'm sure they'll get sorted.