Thanks FrancisA for your reply. A seat just popped up on the LVI-JNB leg on the day I wanted, so just bought that in Club. I just checked the seat map, and it's 5 seats across. Does Comair have proper 2x3 seating (like on SA), or is it the old style CE with the mini B seat, and DEF for sale as normal? Do you have any pictures you could share?
As for getting from Harare over to Vic Falls, that'll be overland...somehow. Hopefully the correct JNB-HRE flight will appear at some stage in Y.