Re the B707. I was told that the CAA served a order to prevent flying on this aircraft when it became clear that it was going to be brought back into use. The order was revoked once the CAA were satisfied that appropriate maintenance had been carried out. There is therefore no reason to believe that the aircraft was not airworthy when it left the UK.

My understanding is that DfT and the CAA are keeping a close eye on some of the less mainstream registers and the action taken with regard to this aircraft and the 3C register seems to confirm this.