Slice pound cake and sandwich with raspberry jam. Cut to fit bottom of large glass bowl with a flat bottom. Soak with sherry. Pour liquid raspberry Jello over all, pricking cake with a fork so it will absorb Jello. Refrigerate until set. Pour on cooled strawberry Jello and refrigerate until set. Make custard according to instructions. Cool and pour over. Cover with plastic wrap and refrigerate until ready to serve. Top with whipped cream and decorate with strawberries.