If you are not in a rush, just keep trying to breach it.

Try also to submit other valid ID's and see your chances. Try everything until you run out of patience.

That's the best option you have since even using escrow for P2P trades, you are still at risk because of Paypal's reversal system and you are the one who will provide bitcoin. Just consider trying other alternatives once all your efforts to pass the Coinbase verification failed.