Melt butter in top of double boiler. Add lemon peel and juice, salt and sugar. Combine eggs and egg yolks and beat slightly. Stir into butter mixture and cook over boiling water, beating constantly with a wire whisk until thick and smooth. Cool.
Spread half of ice cream over bottom of cooled pie shell. Freeze firm. Spread half of cooled lemon mixture over ice cream. Freeze firm. Cover with remaining ice cream; freeze firm. Cover with remaining lemon mixture; freeze firm.
Spread fluffy meringue on pie, completely covering filling (see Perfect Meringue for Topping Pies). Make certain meringue extends to edges. Pie may be frozen and baked later or baked at once.
To bake, place pie on board. Put into extremely hot oven (500°F.) 3 to 5 minutes, or until meringue is lightly browned. Serve immediately.