1007 is owned by the Manchester Transport Museum Society (MTMS) and I believe an appeal is due to be announced soon to raise funds for a depot for it at Heaton Park.
1020 and 1023 were initially retained for departmental use, although these plans didn't come to fruition. I believe they remain operable, at least around the depot.
2001 was retained as it had a lot of money spent on it only a couple of years before withdrawal to return it to service, before it was decided to settle on a full fleet of M5000s. This included a complete rewire by Bombardier to cure a long term bug.