Section 39A. If the estate of a minor under guardianship includes the proceeds of an insurance policy or benefit certificate, the payment of which was contingent upon the death of his parent, the guardian of such minor, if authorized by the probate court, may pay not more than one thousand dollars for expenses for the funeral of such parent, but if said proceeds amount to less than two thousand dollars such payment shall in no event exceed one half of the amount of said proceeds; provided, that such payment shall be so authorized or made only in case the estate of such parent is insufficient to pay said expenses.