made in accordance with an approved pattern and which is or could be marked

, or

first stamped before 1st November 1988 in accordance with the provisions for crane weighing machines constructed upon the hydraulic principle in the Weights and Measures Regulations 1963, or

of the type referred to as “approximate weighers” and first stamped before 1st November 1988, or

of a type referred to as “common form” and which was first stamped before 1st November 1988,