The Department may issue, in the name of the State, revenue bonds of the State, payable solely from the revenues of the Department, at any time after July 27, 1955, for the purpose of refunding at or prior to maturity, all bonds issued prior to such date under the authority of 45 Del. Laws, c. 275, as amended, in an aggregate principal amount not exceeding the principal amount of said outstanding bonds and the redemption premium, if any, required to be paid upon their redemption prior to maturity, the fees and expenses of the trustee named in the indenture and supplemental indentures securing such bonds, the interest which will become due upon such bonds to the date of their redemption and all legal and other expenses incident to the issuance of said bonds, and the Department may deposit with the trustee named in the indenture and supplemental indentures securing the payment of said outstanding bonds, out of the proceeds of such refunding bonds, such amount as shall be required to authorize such trustee to satisfy such indenture and supplemental indentures.