I had a similar problem with a JC Sportline Diffuser I bought. It arrived from the Vendor like this:
It was gonna cost me $500 to send it back to them and they didn't have any replacements in stock so the gave me a bit of a refund and I took it to a local boatbulder who works with fibreglass. He sanded down the clear coat, filled it back in and re-finished it:
Might be worth giving it a try?