If you're going to get a new bonnet and/or respray, then give rubbing compund a try first. It's about 10x more coarse than T-Cut, but doing it gently and consistently should get rid of that. Then use some AG super resin polish to bring it back up to shine. You've got nowt to lose if you're getting a new bonnet anyway...
He has a bit of a problem with the bonnet, why would he be interested in the cost of a full respray?