A brief new thread, just so anybody interested (I still can't believe how many of you were nice enough to post with advice!!) doesn't have to trawl through.
Staggeringly, it seems as if a mere switch to SOAP has pretty much done the trick 
I've not even broken out the new deodorant yet because I've washed with soap these past two mornings and even with my old deodorant I am fresher at 7.30pm than I was at 9.30am that morning I posted.
Only change - soap instead of shower gel.
I can't believe I have let my lovely tops get whiffy all these years when it was a simple a solution as that!!!
I will def try the new deodorants (Sure is my first one to try out) as the problem isn't TOTALLY solved (about 80% improved, though) and I've had relatively non-busy/running aorund days, so I would want a strong, reliable deodorant for a busy or warm day.
But really, for any other sufferers, I had to start a new thread just to say SOAP SOAP SOAP.
What the hell is (or is not) IN shower gel, that it does such a crap job?
Massive thanks again to everyone.
Yours un-whiffily 
Jessicake