I also have a Seicento & a few parts are now getting a little thin on the ground, I have a MK1 899 SPI as my daily which there's only a handful left now which also makes it harder than the 1108/sporting to get parts for , your best bet & probably the easiest way would be eBay for either used or new old stock, breakers yards or find one that's breaking online & request the headlights or as some of us Cento owners are having to do with some parts nowadays go directly to Fiat themselves as on Eper it states they can still order them in, only problem with going directly to Fiat though they are a bit hit & miss with their prices but with some Cento parts that's the only way to get them
Have just found this site selling both left & right Seicento Sporting headlights & apparently in stock, links are here for each light, although they are £104.99 each
Have just found this site selling both left & right Seicento Sporting headlights & apparently in stock, links are here for each light, although they are £104.99 each