Ciao, Lorenzo. I owned an "S" (about 450 serial numbers after the published first one), built in 1969, and a Roadster built in 1970. In the theoretical world of Commando serial numbers*, the "S" was built from March, 1969 to March, 1970 and the Roadster began production as the "S" finished. In my memory -- and note this is 50 years later, and my memory is pretty much first in the long list of things that have become unreliable as I've become older -- the front fender/mudguard stays for the "S" and at least that first year's production of the Roadster were indeed chromed. My '72 had painted stays.
(* For every known fact about Commando production numbers, series, timing, there is a known fact of an exception. If we're talking about production and specs, every sentence should contain the word "mostly" or "probably".)