3. The conditions referred to in paragraph 2 are—
(a)that the vehicle is a model in relation to which there is in force an EEC type approval certificate issued before 1st October 1989;
(b)that the manufacturer of the vehicle has supplied to the relevant authority which issued the EEC type approval certificate, a certificate stating that adapting vehicles of that model to the fuel requirements specified in the Annexes to Community Directive 88/76 would entail a change in material specification of the inlet or exhaust valve seats or a reduction in the compression ratio or an increase in the engine capacity to compensate for loss of power; and
(c)that the relevant authority has accepted the certificate referred to in sub-paragraph (b).