Gary,
FWIW, both my 67's (4B & 5B) still retain their original 346 'WT' master cylinders and neither have date codes on them.
Also, Long Island Corvettes has the correct reproduction covers with the vents and wording (P/N 52-18N).
They also sell the correct steel bale wire for a lot less than others Camaro suppliers.
Merry Christmas,
Mike