I feel for you man!, try to remember who was sitting by you when you got off and on, maybe you see them again and can ask them next time if you catch the train regularly you might see your bag again, or the person sitting next to or around you at the time, I am sure you contacted the conductor and asked, try the lost property section, there is one in all stations, you just have to give description of the bag.
Sorry to say this but I don't think you will see it again, however I hope the nubs and LCD cable die on whoever found it that should happen eventually, let OPENPANDORA STORE KNOW in case the finder sends it back for a repair, phone OP now they should have the serials on it (if you purchased from OP), get insurance to cover it (I don't know how this will work on a pandora, they may actually do you in for an opensource device), contact Craig and order another for 5000 dollors plus VAT).
Demand staff to check CCTV, GO ALL OUT LIKE SCOTLAND YARD!, YOU ARE RUNNING THINGS HERE!
SORRY FOR YOUR LOSS!, WHOEVER FOUND IT (PROBABLY AN OLD PENSIONER PROBABLY WONT KNOW HOW TO USE IT!), AND JUST THROW THE PANDORA IN THE BIN BUT WILL KEEP THE BAG, SO BE ON ALERT FOR YOUR BAG, DID YOU HAVE ANY DETAILS SUCH AS ADDRESS/NAMES ON BAG, DID YOU HAVE YOUR CV IN THE BAG OR ANY KEYS?, IF YES WATCH OUT FOR THE PERSON COMING TO ROB YOUR HOME, REPORT IT TO THE POLICE ALSO, IN THE END YOU WILL NOT ACHIEVE MUCH FROM ALL THIS UNLESS AN HONEST PERSON FINDS IT AND GIVES IT IN, BUT THEN AGAIN IF A 1ST BATCH PERSON FINDS IT, THEY MAY THINK TWICE ON HANDING IT IN