Genuine Regina Extra 428 chain, as fitted by most Italian motorcycle factories, years ago. My research shows it should be long enough for the smallest bevel Ducati. Length is 115 link (about 57"), please measure your app before purchasing. Includes master link. This chain is also factory fitted with a half-link, the beauty of which means the chain can be cut to either odd or even length, your preference.
Likely also fits smallest BSA and Triumph.
Supplied in original packaging. Grease is fresh and icky, even after all this time.