When my expansion bottle is filled up it always seems to blow out a fair bit of it when stopped via the overflow breather ,,,is this normal or a common fault with Surfs as it has always done it, temp gauge moves very slightly but not too much, so no worries on that part, just the hassle of having to...

I suspect the alternator (again).

The batteries where replaced about 9 months ago in Russia and have both been holding the correct charge (although one has always been about .3v higher than the other).

The car had the alternator bushes replaced in Morocco about 3 months...