Goods comprised in a hire-purchase agreement or goods comprised in a conditional sale agreement which have not become vested in the debtor shall not be treated in Scotland as subject to the landlord's hypothec-
(a) during the period between the service of a default notice in respect of the goods and the date on which the notice expires or is earlier complied with; or
(b) if the agreement is enforceable on an order of the court only, during the period between the commencement and termination of an action by the creditor to enforce the agreement.