No operator, firm or individual not approved as a shop operator will be permitted to engage in the repair, service, overhaul or maintenance of aircraft or engines on the municipal airport for remuneration or reward. The only exception to the above shall be in the case of aircraft dealers who are required by the factory they represent to provide certain limited service for a prescribed length of time on new aircraft sold by them. In this case, factory-dealer service only will be permitted. Authorization for such factory-dealer service shall be submitted to the airport manager for approval. (Prior code § 4.02.029)