Refurbishment, servicing and repair of obsolete rail electronics.
Because something is obsolete, it doesn’t mean that it can’t be supported. It doesn't meant that it can't be repaired. It doesn't mean that you have to upgrade it.
This is especially true when it comes to electronic equipment used on the rail network.
Take this sample of electronic items, these are some of the control electronics used in a class 43 HST power car locomotive. (An Intercity 125 if you remember those and the adverts on TV with one jokingly being pulled over by a police train!)
The locomotives were built by British Rail Engineering Ltd between 1975 and 1982, over 40 years later and they're still working on our rail network. These PCBs and controls are an upgrade to the originals however they're obsolete and no longer supported by the OEM.