I agree, I think those might be custom finished, as it does not have the Campagnolo logo. Is it paint/powdercoating or anodizing?
The aluminum/anodize finish used on the covers for the Campy Deltas were on the soft side and tended to get beat up really easily just from grit thrown up by tires, literally sandblasting them, etching and pitting the surface. That's why maybe this set was re-finished.
You can strip off that white finish and just polish the dovers if you want them to look close to original. They are beautiful calipers anyway, no matter what finish is on them.
it sort of looks like that stuff they put on new cars to protect the doors and fenders from scrapes. but I agree I don't think it is OEM option.
Bianchis '87 Sport SX, '90 Proto (2), '91 Boarala 'cross, '93 Project 3, '88 Trofeo, '86 Volpe, '89 Axis, '79 Mixte, '99 Mega Pro XL Ti, '97 Ti Megatube, , '90 something Vento 603,
Others but still loved,; '80 RIGI, '80 Batavus Professional, '87 Cornelo, '86 Bertoni (sold), '09 Motobecane SS, '98 Hetchins M.O., '09 K2 Mainframe, '89 Trek 2000, '?? Jane Doe (still on the drawing board), '90ish Haro Escape
Thanks for your help guys. It never even crossed my mind that the white was applied later. I've decided not to buy them.