I suspect this might have actually been 345007 returning to Ilford yesterday since 345008 appears to have been reported at Old Oak Depot later in the day. There doesn't appear to have been a movement in the other direction.
View attachment 102105
[Picture shows a screen shot of output from TrackIt! with headcode '5I08' moving between signal berths C412, 0142 and C313 at Old Oak Depot around 1745 on 2 September].
You are right it was 345 007 that got dragged over yesterday, I saw it go through Forest Gate that afternoon behind 37800.