Number series confusion
 

I have listed the Continuous Welded Rail Train Numbers and formations
Today I observed one passing through my home station
Totally confused me as the wagons had totally different numbers

The train is formed of

Chutes (numbers DR89200-89215)
Chute wagon (numbers 979500-979515)
Power Wagon (numbers DR89000 890015)
Inner Wagons x4
Clamping Wagon (numbers 979400 - 979415)
Inner Wagon x4 (numbers DR79000 - 79127)
Stabling Wagon (numbers 979600 - 979615)

Consist is

66131
FJA 621916
Chute Wagon 979512 (with Chute 89212)
93418
93729
93613
93614
93726
93727
93702
93707
93709
93701
93700


So can anyone help me with these different numbers

You might take a look at the OTP website.
http://www.ontrackplant.com/photo/979512-1
Is it possible that the 2 numbers are for pre and post rebuild?