I bought a couple from eBay that others have recommended. I think they're from a C2. They weren't great those because they wouldn't sit flush to the bonnet.
Did you know that you can get a pin and move the jets to a different angle? You might find that yours are pointing at the bottom of the screen. They're very easy to remove and check, you basically just pull them out of the bonnet. You might want to clamp the hose those otherwise they will disappear down the hole and you'll need some needle nosed pliers to retrieve!