easy enough to tell, without having the gun and you can SEE a picture of the grips........the hole pattern on the panels will determine what the grips are , as to what gun YOU have, simply by looking at the LOWER grip screw of the panels....the OLD ( A-54) frames the left panel grip hole at the bottom is closer to the bottom ( lower) on the left ,than on the right....the opposite for the later ( A-100 ) frame, the lower hole is over on the right panel...can tell simply by LOOKING at the grips panels and the location of these LOWER screw holes...this NEVER fails.....................the only thing to worry about later is if the MK II versus MK I , and the hold open slot for the MK IIs when used on the later MK Is....gotta "fill" this void on the left panel...... :wink:
Happy New Year