If a general bidder customarily performs any of the four classes of work specified in subsection (a) of § 4b-93 or any other class of work included by the awarding authority pursuant to said subsection, the general bidder may list himself as a subcontractor together with his price in the space provided in the bid form. A listed sub-bid so submitted by the general bidder shall be considered on a par with other listed sub-bids, and no such sub-bid by a general bidder shall be considered unless the general bidder can show to the satisfaction of the awarding authority, based on objective criteria established for such purpose, that he customarily performs such subtrade work and is qualified to do the character of work required by the applicable section of the specifications.