Where are you getting your Libertad information from?
From 1982 to 1995 they were 38mm
From 1996 to present they are 40mm
From 1982 to 1999 the obverse had the Mexican Coat of Arms, an eagle holding a snake.
From 2000 to present the obverse depicted a smaller version of the coat of arms surrounded by the coat of arms of each of the ten Mexican states. To sum up all the varieties :
1982-1991 38mm Obverse: Eagle standing on cactus with seven dots; Reverse: Winged Victory facing forward, ONZA in large letters.
1991 for what ever reason and not announced or presumably counted, along with the regular mintage of 1991's described above, some "mules" were also minted, 38mm Obverse: Eagle standing on a cactus, but with eight dots (the design of proof Libertads); Reverse: Winged Victory facing forward with OnZa written in alternating letters.
1992-1995 38mm Obverse: Eagle holding a snake on cactus with seven dots; Reverse: Winged Victory facing forward with OnZa written in alternating letters.
1996-1999 40mm Obverse: Eagle holding a snake on a cactus with seven dots; Reverse: Winged Victory facing to the side.
2000-Present 40mm Obverse: Small Eagle with snake surrounded by ten smaller coat of arms; Reverse: Winged Victory facing to the side
Five varieties all together if you don't count the 1987 Double Die.
From 1982 to 1995 they were 38mm
From 1996 to present they are 40mm
From 1982 to 1999 the obverse had the Mexican Coat of Arms, an eagle holding a snake.
From 2000 to present the obverse depicted a smaller version of the coat of arms surrounded by the coat of arms of each of the ten Mexican states. To sum up all the varieties :
1982-1991 38mm Obverse: Eagle standing on cactus with seven dots; Reverse: Winged Victory facing forward, ONZA in large letters.
1991 for what ever reason and not announced or presumably counted, along with the regular mintage of 1991's described above, some "mules" were also minted, 38mm Obverse: Eagle standing on a cactus, but with eight dots (the design of proof Libertads); Reverse: Winged Victory facing forward with OnZa written in alternating letters.
1992-1995 38mm Obverse: Eagle holding a snake on cactus with seven dots; Reverse: Winged Victory facing forward with OnZa written in alternating letters.
1996-1999 40mm Obverse: Eagle holding a snake on a cactus with seven dots; Reverse: Winged Victory facing to the side.
2000-Present 40mm Obverse: Small Eagle with snake surrounded by ten smaller coat of arms; Reverse: Winged Victory facing to the side
Five varieties all together if you don't count the 1987 Double Die.



























