1. A Community design shall be deemed not to have had, as from the outset, the effects specified in this Regulation, to the extent that it has been declared invalid.
2. Subject to the national provisions relating either to claims for compensation for damage caused by negligence or lack of good faith on the part of the holder of the Community design, or to unjust enrichment, the retroactive effect of invalidity of the Community design shall not affect:
(a) any decision on infringement which has acquired the authority of a final decision and been enforced prior to the invalidity decision;
(b) any contract concluded prior to the invalidity decision, in so far as it has been performed before the decision; however, repayment, to an extent justified by the circumstances, of sums paid under the relevant contract may be claimed on grounds of equity.