Combine gelatin, sugar, and salt in top of a double boiler. Combine egg yolks and milk; mix well. Gradually add to gelatin mixture, stirring well. Place over boiling water; cook 10 minutes, stirring constantly, until mixture is thickened. Remove from heat; stir in vanilla. Set aside to cool.
Fold coconut into cooled custard. Spoon 1 tablespoon coconut custard into each tart shell. Top each tart with a dollop of whipped cream; garnish with strawberry halves, if desired.