I can say that Cdn Aviator is correct in his comments. Having flown on the aircraft in question as crew, and lived through the reconfiguring to the AAR role, it is fairly simple to tell which aircraft have been modified. On the inside, just as you enter the upper cargo area, there will be a refueling console in a locked cabinet, with rails on the floor to install the seats. The last I had heard, 001, 002, and 003 were all still in full pax config and although 004 and 005 were in combi/AAR config, they were only being used in an AAR role. There has been some recent discussions on converting 003 back to a combi configuration, so that we would have one VIP config, one gull pax config, one combi config, and two AAR configs.