The 2 motor cars from 507022 ARE still in use.
The DMS A Car from 507022(no 64426) is now part of a 314 unit in Scotland.
The DMS B Car from 507022(no 64388) is now the DMS B car in 507004 (the unit it collided with) The DMS B car from 507004 (no 64369) has been scrapped.
The centre car from 507004 was less damaged in the collision that the centre car in 507022, so they decided to use keep 004, however the DMS B car in 507004 was damaged more than the DMS B car in 507022.
I hope they donate parts such as door motors to Merseyrail to keep them going for as long as possible!
Just to tie this one up:
Carriage 64426 (ex 507022) is now part of 314203, reformed 1996.
Carriage 64388 (ex 507022) has replaced 64370 in 507004's formation, reformed 1991. 64370 nominally renumbered as part of 507022 before being scrapped at McMetals with redundant 507022 trailer 71363 in December 1996.
Neither trailer car was damaged in the collision as far as I know (certainly 507022's wasn't). They chose to keep 507004 likely due to its earlier numbering within the class.
Unfortunately, I doubt the door motors would be compatible. Merseyrail's fleet had its doors and door air system replaced as part of the refurbishment in 2002-05. There isn't much in the way of interior parts that could be re-used, and a lot of underfloor equipment would need replacing given the length of time these units have spent on the sidelines.
