All work done by a repairer for which a separate charge is imposed upon a customer for such work, except for work represented by a charge to the customer in an amount less than twenty-five dollars, shall be recorded on an invoice and shall reasonably describe all service work done and parts supplied. If any used parts are supplied, the invoice shall clearly state that fact. If any component system installed is composed of new and used parts, such invoice shall clearly state that fact. One copy of the invoice shall be given to the customer and one copy shall be retained by the repairer for a period of not less than one year. The repairer shall make available to the customer, if requested at the time a work order is placed, all replaced parts, components or equipment, excepting any parts, components or equipment normally sold on an exchange basis or subject to a warranty. The obligation to make available replaced parts, components and equipment shall not apply to any part, the dimensions of which are less than one-quarter of an inch, when replaced by a jeweler, watchmaker or silversmith.