1969 Camaro dealer sales literature has detailed descriptions of what is included with the various option packages. "Camaro SS exterior features" does not list "bright headlamp trim" but style trim group does. The same description is repeated in the ordering info, salesmans' booklet and the three revs I have of the dealer order form.
The July 1969 Super Stock magazine road test of one of the first Yenko Camaros, known to be X66, clearly shows plain headlamp bezels.
The May 1969 Hi-Perf Cars road test of a non-style trim 396/375 Camaro SS also shows plain headlamp bezels.
Based on these original vintage road test photos and Chevrolet ordering info there is no reason to believe a non-style trim Camaro SS would have chrome-trimmed headlamp bezels.