^Good point, I never thought of that!, but wait a sec, didn't Spock where a cloak and hood when he was in public? Or am I remembering that wrong?
Then why didn't he just get plastic surgery before arriving on Romulus?
The Romulan helmets seen on TOS were hiding many a ridged forehead. Maybe when the Romulans left Vulcan, most of them were of the ridged type?