The original (as delivered on the engine) did not have this. I sent out some emails to try and ascertain if/why this is now required. Chris, Peer, and Todd were unable to help. I contacted Leon at Polini Parts and he requested my 303 Serial Number to get a response from Polini Italy. We are awaiting that info before proceeding with the installation.
In the meantime, I have started to mask out the cowling "bumps" for painting black. I will run a thin strip of clear sealant along the edges for a crisp outline. Having been warned about the possibility of incompatible solvents, I just came in from running a test on the clear cowl paint/clear sealant/gloss black for compatibility. So far all seems well but will check again i the morning before spraying the black
It's good to be back building again.