Mix the crumbs, coconut, and melted butter. Reserve 1/2 cup of this mixture for the top; press the rest into the bottom of 2 cake molds. Drain the pineapple and reserve 1/2 cup of juice. In a small saucepan, combine the juice and rum, sprinkle with gelatin. Heat over low heat, stirring, until the gelatin is dissolved. Remove from heat. In a small, thick saucepan, beat together the egg yolks, 3/4 cup of sugar, salt, and milk. Cook over low heat, stirring constantly, until the mixture has slightly thickened; do not boil. Then incorporate the gelatin mixture. Beat the cream cheese until smooth, then incorporate the egg yolk mixture, followed by the pineapple. Refrigerate until the mixture has slightly thickened, stirring 1 to 2 times. Whip the egg whites until they form soft peaks. Gradually add 1/4 cup of sugar, beating constantly, until stiff peaks are formed. Gently incorporate the whipped egg whites into the creamy mixture. Pour the mixture into the 2 molds. Sprinkle the top with the reserved crumb mixture and refrigerate for at least 4 hours.