I know in the Sprint they went to stainless steel with the 101. I would assume the same for Spider as I know there was stainless up in the dash trim, but I can't be sure. I'm sure somebody with more knowledge will chime in.
My '56 Spider seems to be very original (low miles, stored since the early '80's). It only had one rocker trim on it, and it was pretty old and beaten up looking, but it was stainless. A lot of the other trim on the car is chrome-plated brass.
My mistake, ctossi, I am an idiot. My initial assessment that my rocker trim was stainless steel was based on an inspection of a damaged area. After seeing how Joe ground into his trim to inspect it, I did the same and discovered it is brass, not stainless. A closer inspection of the damaged area also shows that where the damage is deepest, it shows brass. I am now thinking that at least some of the first 1000 cars had brass rocker trim.
I owned a 1957 Spider which was purchased in 1973 and the rocker trim was chrome plated steel. I restored a 1956 Spider and 1959 Spider and both cars had chrome plated steel rocker trim. I do not think that stainless steel was used on 750 Spiders. I purchased new eyebrows for my 1957 Spider from Alfa Romeo around 1975 and were stainless steel.
Just checked my 59 750 series spider trim pieces and they are stainless...easy to check as they are currently in a pile waiting to be reinstalled after paint, question...do the eyebrows have any type of gasket between them and the body... never took them off any spider and they were missing from this project when I bought it..have not seen any repros for sale
No there was no gasketing between the eyebrows and the body on the Spider when new - in practice some people do choose to fit something between the trim & the paint, options do include a black rubber U strip, some folks have slit clear plastic piping and some have carefully laid down a bead of clear silicone onto the edge of the trim & allowed that to cure before fitting.
The only Giulietta / Giulia to have the black U shaped "Licorice" gasket originally was the Series II Sprint & then only on the center heart.
In practice I generally fit a very thin U shaped black rubber to everything, yes I know it's not strictly correct, but it's my paint & I try protect it as much as possible. The next custodian can remove it.