It's been removed but is available to refit.
They were out of guage for much of the route and operated under some pretty stringent conditions and for a time were limited to East Croydon platform 5 only, not to mention the whole of the WLL they were OPPOS for passing freights. But they were a stop gap that worked.
OPPOS = http://author.rssb.co.uk/rgs/rulebooks/GORT3056-2 Iss 2.pdf
Was reported at the time that due to the delayed 377/5 causing issues the 350/1 clearance was obtained in just six weeks from idea to being able to run. Quite an achievement.
But form an operators point of view they ran with a list of restrictions longer than your arm with admendments continuously being updated, like the use of more platforms at East Croydon, followed by access to Selhurst Depot via Selhurst, then after a bit longer via Norwood Folk Arrival/Norwood Station (reverse and not all platforms). I don't think they ever got passed for the Up/Down Victoria/Brighton fast lines from East Croydon to Balham, if they did then the paperwork never got admended at our place.