Local seller had them with a hotrod that was never installed. He went OEM on the Hotrod. 20 bucks new in the box but warning these draw way too much through 40 plus year old circuits, so a 40 Amp rated relay is a must. with lamp pigtails and a direct power feed from the battery to the relay...
Update to the thread, the compression bumper mounts should be able to rotate that flange, unless rusted like those above. So 76 an77 should work on 78 & 79