I received an email from a fellow endowment holder, who has a policy dating back before 1988.
His initial complaint was rejected by the major building society who sold him the policy, as it was pre 1988.
However, he received a letter from them recently which said that they have been passed details of his appeal against their decison by the FOS.
They have again reviewed the case, and they will now uphold the complaint after all.
It seems that the 1988 rule is flexible after all; just as the claims company that is handling my pre 1988 case have indicated to me.
Maybe we will get somewhere.