Thank you Lewlew for keeping me updated with 3543, hopefully soon it maybe available for passenger work.
If anyone has any information regarding the stopped central line units that I am looking for would be appreciated. Thank you.
91111 - part of the refurbishment programme (CLIP) nominal expected return 31/12/2021
91155 - part of the refurbishment programme (CLIP) nominal expected return 01/05/2022
91263 - part of the refurbishment programme (CLIP) nominal expected return 31/12/2021
91293 - stopped awaiting sign off (it doesn't say what for) the expected return date has just past: 30/04/2021, so perhaps this one will be in service soon...
91331 - part of the refurbishment programme (CLIP) nominal expected return 01/05/2022
91337 - awaiting materials (having been long term stopped since September 2018) - expected return listed as 31/12/2020, so don't hold your breath on seeing this one soon...
91341 - project to return to service appears not to have resumed so far (it was suspended in the first lockdown last year) and the return date is shown as 31/12/2021
It looks like your best bet for one this year is 91293, though difficult to say about 91331. I doubt you'll see the CLIP trains or 91341 this year...
HTH