In central Jersey [08902] Came out of a Wildcat Sport Coupe. Hinges move well. Only missing 1 bolt. The bolts look rough, but the 2 clean ones hit the wire wheel for like 15 secs and came up completely clean. $80 for all, shipping extra. Also have the door jamb splash guards (from manual window car). I've seen the exact same hinges for sale advertised as '63 Pontiac. Likely the same for '64 also.
Upper: Hollander #2 - '61-'64 GM full size (BOPC ) Lower: Hollander #7 - '61 - '64 GM full size (BOPC also states Cadillac Except for Limo/75 series) These do not fit Riviera. Ancient numbers which are likely long ago superseded / discontinued.