By the act of paying or submitting to any Federal Reserve Processing Site, any TRS Site, or any Treasury office authorized to redeem securities, a security on which it has affixed the special endorsement, a paying agent shall be deemed to have:

(a) Unconditionally guaranteed to the United States the validity of the transaction, including the identification of the owner and the disposition of the proceeds or the new bonds, as the case may be, in accordance with the presenter's instruction;

(b) Assumed complete and unconditional liability to the United States for any loss which may be incurred by the United States as a result of the transaction; and

(c) Unconditionally agreed to make prompt reimbursement for the amount of any loss, upon request of the Department of the Treasury.