Send an email to Jim Cockerham in Winston-Salem who's the club president of the Carolina Thunderbird Club. He might know a good local source for those bumpers. His email is
[email protected].
If no luck, try Hollywood Classic Cars in Hallandale, FL who have parted-out and restored over 200 Tbirds. They advertise used bumpers from only $50. They might also sell them re-chromed if you don't have a trusted local chrome shop. Their website is:
http://t-bird.net. Or call (800) 235-2444 and ask for Mel.
Good luck!!