the first one is a late G, as evidenced by the ball mount Mg and the chinned mantlet -that squared off section under the barrel-
Also not in the picture, the late G would have different exhausts , two possible types, and a raised 'tower' on the rear deck for the crew compartment heater.
The next two are Late A models. Evidenced by the stepped side armor at the rear- obscured in first photo, but the G's have smooth sides at the rear, - the commanders cupola is NOT the drum type, and both have ball mg mounts as well.
Hope this helps.
Order of production was D for Damlier, then A for Alkett, and then G.. there were no B,C,E
The F was to come on line as the war ended, and the Panther II died on the drawing board.
Welcome to my madness ...panthers that is.. have a nice day
Mike