Peter, all our flights had Delta flight numbers; we had paper tickets that Delta had issued. The JNB/ATL flight # is DL 799. JNB/CPT was DL7798.
I paid Delta nearly $8k (7995.07 to be exact) for my ticket, so I thought I should get Delta miles. The tickets were reissued on April 9, '06, by Delta, because of a small routing change (a few minute change in a couple of flights).