Oven bits and pieces / cleaning

[cookingfat]

Just had oven cleaned by a local firm - god, I love it, it looks like new.

However, they don't do the grill pan or the drip tray/baking tray, and these are SO scuzzy I'd like to bin them and buy new ones. But where from? (It's an IKEA/Whirlpool oven if that matters).

Also, on the hob, the bits where the pans go (not sure of the technical terms) are blackened rather than stainless steel. Any top tips to restore these to their former glory? I shove them in the dishwasher sometimes, but it doesn't quite do it.

I use Oven Mate only available from Lakeland, the best oven cleaner in the world! It would bring up the grill pan etc like new. Have also used that one that comes with a plastic bag to put the shelves + cleaner in for doing shelves when I had run out of Oven Mate, that was quite good too.
With regard to the stainless steel bits, I just don't know as I don't have any.