So the plumber tore the wall opened and replaced the old shower unit. So he did not replace the wall.
I have to say with some pride that Liz and I (I mostly under her instruction) replaced the dry wall (including cut it to size and peared holes in it for the spout and shower knob), installed it, adheased the shower plastic back onto it and cleaned it all up.
That was the first small victory.
The second was that when we turned the water on nothing exploded or sprayed or otherwise went horridly.
The thrid victory was that the new shower pieces worked.
The only remaining concern is that the shower spout still leaks somewhat. FAR FAR less than before but it is still leaking. I might get the plumber to come back if only because he's now relatively familiar with teh system. I also no longer think this new small leak will require him to pull out the wall again as we've done that. I'm convinced that the problem now is is somwhere in how we installed the hand knob or the the shower spout.
I think we're almost there but at least now the drips are by drop and not by stream! The way they were before.
The fun of a house... ARE YOU LISTENING MARK! :) Hey... at least we're in this together now.
PS OFF TO GERMANY TOMORROW WITH A STOP OVER IN LONDON. HUZZAH!