With the rollout of new stock by various operators underway a number of Class 153 were surplus to requirements. Some moved to other operators to augment their services with Network Rail purchasing three in May 2021. Two of the three that they acquired are seen stabled in Norwich Yard adjacent to the station. 153376 and 153311 still wear their EMR liveries but are now debranded having the addition of various recording equipment. I suspect that Network Rail will get round to painting them in their house yellow paint scheme unless the take over by the fabled GBR changes this? The last time that I saw 153311 was less than a year ago with it heading to Wolverton Works for attention just six months before its change of ownership, see......
https://www.ontheupfast.com/p/21936chg/29876083204/x153311-10-30-etches-park-wolverton