The office of a professional person limited to lawyers, accountants, music teachers and artists, provided that such persons reside on the premises. Not more than two persons other than a resident of the premises shall be employed by such professional person and that not more than 1/2 of the floor area of one story or the basement shall be devoted to such use. No merchandise or materials, either assembled or unassembled, may be received into a residence for the purpose of assembling, fabricating, storing or reselling. No use permitted by this section shall result in any permitted professional use operating in this zone in other than a building strictly residential in appearance. Except for permitted signs, there shall be no physical evidence of said use visible from the exterior of the building so used. Such use is subject to the requirements of §
134-8.