Adding an anonymous object type to an observable array

[Rob L]

I'm working on a simple application using MVC4 that allows me to display each individual item in an observable array to the end user, and then provides basic CRUD functionality such that a user can add, edit or delete items.  

I create my observable array in the following manner:

  function Ob ligorViewModel() {     

   var obligorArray = ko.utils.parseJson('@jsonModel');

        self.obligors = ko.mapping.fromJS(obligorArray, mapping);

   this.selectedObligor = ko.observable();

    this.removeObligor = function (obligor) {

            self.obligors.remove(obligor);

        },

   this.editObligor = function (obligor) {

            self.selectedProduct(obligor);

        };

        this.addObligor = function () {

            self.selectedObligor(new ??());

        },

   ... etc.

}

I'm trying to figure out if it's possible to instantiate a new instance of the obligor element without having to define a viewmodel for that object type.  It seems to be possible to edit or delete anonyous object types using the datafor or contextFor helper methods in KO, but I haven't been able to determine if there is a manner in which you can instantiate a new anonymous type.

I'm primarily trying to avoid having to define an obligor viewmodel in JavaScript as well as in C# (this is an MVC4 application) so I can avoid issues where the C# definition is changed but the JavaScript definition is not.  

Any help would be appreciated.