Hello all, I was just pulling into Stratford on the Central line Westbound and I noticed a pair of 317's pulling in on Platform 5 adjacent to me Liverpool Street bound. I know that the plan is that three of them will work the 17.02 to Norwich from December, but I didn't realise they had any current booked GEML work. Could anybody tell me what service they would've been working? They pulled in at 20.42, and one of them was number 881 if that helps. Thanks.