Further to my previous post. Oven cleaner here in the UK seems to be in short supply, our local Tesco supermarket hasn't any and doesn't now when there will be any in.
I went to my local small hardware store that sells my Plasti-Kote sprays and he said that Ammonia would do the job as oven cleaner has a high percentage of ammonia in it.
I tried it yesterday but OUTSIDE! The fumes are shocking.
Later in the day, not wanting to leave it outside for cats/wild animals or birds attempting to drink it. I tested it the fumes had gone so took it indoors, added very hot water and washing up liquid and after cooling down all the chrome coating had gone as has the slippery coating that oven cleaner leaves behind!
Sorted! This morning I put back and fronts of chromed wire wheels from an Alfa Romeo kit in the plastic tub, lid off. The Alfa has gloss black wires in the 1:1 version!