Thanks for comments....
.... but I eventually sorted it out. To be honest I cannot remember exactly what I did differently, but I started again from scratch. I am now up and running and have my first app on the market. (A simple calculator called TrueCalc, which has the distinguishing feature that you can record your work and email what you did to yourself (or anyone for that matter) as a permanent record. I did it mostly for my own satisfaction, being semi-retired, and have since got involved on some more (financially) productive work in c#, so there may not be any more Android apps for a while.