They are with few exceptions, all the same from the 60's to the 90's. Electrical plugs vary depending on the year, some have different support brackets and I have seen on a '75 that the screw that holds the tin cover over the gears uses a different hole in the case so instead of 3 bolts holding the motor to the regulator in my 66, I can only use 2.
Dorman 742-300 and 742-301 are new replacements. $40 give or take.
Kevin