So I went to check the sticker and its gone.
The cabinet has now been stencilled with 6 on all panels 
Strange ... FTTC cabinets don't normally get numbered ... any numbering goes on the PCP.
However, given that it is over 200m away from the original cab 6, which ought to be impossible, I wonder is something else is going on.
It could turn out that there's some copper re-arrangement going on here, and that an AIO (all in one) cabinet has been put in place. That would, I guess, get numbered as it has both PCP and FTTC cabinets in one.
Can you confirm what the cabinet looks like, by comparing to these:
http://www.robertos.me.uk./html/street_cabinets_etc....
or
http://www.kitz.co.uk/adsl/fttc-cabinets.htm
(RobertoS ... time for an AIO picture!)
The estimated date of completion of this cabinet is mid of August 2017 which may change in future depends on the physical amount of work left.
I was going to comment that this was rather late for BT to still be installing CDS cabinets ... but it turns out cab 6 is a commercial one. Now CDS phase 1 is finished, BT must be going back and completing the missing commercial cabs.
That would also go against what I suggested earlier ... copper rearrangement doesn't happen on commercial cabs.