A Class 1 definitely IS valid for Class 2 privileges. The CAA confused everyone by changing things so that it wasn't, then changing it back again. For a while you had to get a sticker from your AME saying this was the case, since the certificate itself no longer says it. Now, according to my AME, you don't even need that. But you are definitely OK. However, for your own peace of mind, why not ring the CAA or any AME and check?