So reading all this, am I correct in thinking that my newly minted JAR-FCL PPL allows me to fly above a cloud layer, not in sight of the surface provided I'm 1,000 feet above it?
It would in theory now be perfectly legal to climb through a hole in the cloud layer to reach "VFR on top", and then descend through a hole to get back under the cloud? Or take off in clear skies, fly over a layer of cloud en route (and be out of sight of the surface) and reach clear skies the other side?

I think the PPL syllabus needs revising!

Yes.

VMC on top without sight of surface has never been in the slightest way enforceable, anyway.

What you always needed to do is be sure you can get back down :)

This method has been very popular for touring to southern Europe, by IMC Rated pilots, because you can depart the UK in mucky wx (using the IMCR privileges), fly VMC on top (once out of the low level UK Class A), across / into France between FL065 and FL115 in their extensive Class E airspace (which is uncontrolled airspace for VFR), or similarly into Germany, and then descend to the destination in nice wx conditions that tend to prevail down there (unless you messed up).

And the opposite on the way back.

Every one of my long VFR trips involved heavy use of VMC on top.

What makes you say that? I'm not sure I understand. Do you mean the burden of proof is so high as to make it nearly impossible to prove you were out of sight of the surface?