Is that actually orange/white in no. 2? Looks more like white/orange. (First color is "main" color, second is bands.)
Either way, the existing wiring is certainly not following the standard coding, which is:
2 - Blue/white
3 - Orange/white
4 - White/orange
5 - White/blue
White/orange (4) is not normally used, and as mentioned already, many newer devices do not use the orange/white (3).
As for numbering, there are some sockets on the market which have 1 - 6 numbered in reverse, due to a monumental blunder in the original numbering scheme and misunderstanding on the part of the manufacturer of the jack. However, if you are using devices which don't need the ringer wire (3), then 2 & 5 will just be swapped with reversed numbering anyway, and almost no newer devices are polarity sensitive.