Melt the butter in a 6-inch heavy skillet and set aside.
Combine the flour, sugar, and salt in a bowl.
Add a mixture of eggs, milk, melted butter, and lemon peel; beat with a hand rotary or electric beater until smooth.
Heat skillet to moderately hot.
Pour in just enough batter to cover bottom.
Immediately tilt skillet back and forth to spread batter thinly and evenly.
Cook each crepe over medium heat until light brown on bottom and firm to touch on top.
Loosen edges with spatula.
Turn and brown second side.
It should not be necessary to grease skillet for each crepe.
As each crepe is cooked, transfer to a hot platter, spread generously with the desired butter and roll up.
Spread some of the butter over each rolled crepe.