A wire brush, two large bits of wet and dry paper and lots of elbow grease later, Oz is now ready for a coat of pot belly black. The same cannot be said for the cooking plates which have been soaking in some white vinegar as we speak. A good friend, Hutchy, passed on to me that she had read about the virtues of vinegar as a rust removal aid, on the internet, at some stage. I was willing to try anything that may help.
A few hours later I hit the plates with a solid effort of steel wool treatment. All the rust has now gone but the plates have been left pitted, and of course, not the prettiest looking things to be cooking on. There is no other answer. It's POWER TOOL TIME!!! (This happens to be the grinder with an emery attachment)
And when Summer comes again I need to remember to 'slip, slop, slap'. Slip Oz into the shed, slop some oil on his cooking plates and slap on a cover. I am off now to forward plan that in the diary so I will remember.