I have seen the screw on the back of late '50's/early '60's Specialissimas and assume it is to provide lubrication for the headset. My Competizione does not have the screw. My bike is a bit later - circa 1964. I wonder if this screw was only common to the Specialissima, or if it was discontinued on both the Specialissima and Competizione models by 1963 or '64?
Jeff Pyzyk
Screwless in
Milwaukee, WI