I escalated my dispute, as like you, the seller did not respond to any e-mails. However, yesterday I had an e-mail from him (not via Paypal) to say he'd shipped the correct bumper to me and if I could cancel the dispute once I was satisfied it fitted correctly. Whether it's painted or not remains to be seen as this was my bone of contention with him.
It's weird he doesn't use the Paypal resolution forum to mail back, there's only 3 days to go for him to reply to me through there otherwise I win by default.
Will keep you all posted.