As previously noted, in some cases the related activities performed through unified operation or common control for a common business purpose which are included in the enterprise under the definition in section 3(r) of the Act may include activities other than the wholesale or bulk distribution of petroleum products. Examples are tire recapping or gasoline station services, the sale and servicing of oil burners, or the distribution of coal, ice, feed, building supplies, paint, etc. In some instances, as in the case of oil-burner servicing, these other activities are customarily performed as an incident to or in conjunction with the wholesale or bulk distribution of petroleum products in the enterprises of the industry engaged in such distribution. As indicated in § 794.104, employees of the enterprise who engage in such activities are within the general scope of the exemption. However, activities which are not customary practices of enterprises in the industry of wholesale or bulk distribution of petroleum products are not within the scope of the intent of the section 7(b)(3) exemption. For example, construction activities, operation of a sporting goods store, scrap paper and metal activities, the operation of a general repair garage, etc., are not the type of activities for which the section 7(b)(3) exemption was intended. Thus, where an enterprise engaged in the wholesale or bulk distribution of petroleum products operates a general repair garage, a mechanic servicing the automobiles and trucks brought to the garage by customers will not for that reason be within the exemption provided by section 7(b)(3), although the exemption provided by section 13(a)(2) may apply to him if the garage qualifies as an exempt retail or service establishment under the tests provided in that section of the Act. On the other hand, mechanics employed by an enterprise engaged in the wholesale or bulk distribution of petroleum products for the purpose of keeping the distribution equipment of the enterprise in good repair would come within the 7(b)(3) exemption.