Pre-74 Aga 'Deluxe' cookers were often solid fuel when sold. You can tell if your cooker has an air wheel like the one shown below; its located in the top left hand corner of the front.
If your cooker was subsequently converted to gas then it will have a diverter stand that looks like the picture below.
On top of this is the diverter itself. This is often black plastic and they are ugly and impossible to clean. They were of course cheaper than the proper enamelled ones! It looks like the below.
Together they look like this...
When we re-enamel cookers like this we need to remove both to replace the main hob. We can replace with the originals but always prefer to use new ones. Our new diverter stands look like this.
And our lovely, proper!, enamelled diverters look like this. Easy to clean and gorgeously long lasting.