Retail service shop, such as a bakery, ice cream or similar shop, custom tailoring or millinery shop, clock, watch, or jewelry shop, or household appliance repair shop provided that:
(a)
Any processing activity shall be not less than 15 feet from the front of the building and shall be screened by a wall or partition from the front portion of the building used by customers; and
(b)
Any article made shall be sold at retail from the premises; and
(c)
The area devoted to processing shall constitute not more than 30% of the gross floor area.