BRL, thanks for the advice. I'll have a try again in a couple of months. My original post on this forum is now on about page 3, so hardly likely to be spotted now.
There is always hope in the C & LA forum as I am still on the front page (although it seems that nobody much ever visits there !!!)
Maybe - like with Tenerife and Crete, I'll won't get any knowlegable answers and will end up researching it from scratch myself.
TMF