Help with Parking Brake Module on 2007 S Type

[TimD]

Hi all. I am having some issues trying to decipher which numbers I need to match for replacing my parking brake module.
So far I have deduced that:

1. the two letters at the end of the P/N do not matter.
2. The S/W number needs to match

Could people please correct me if I am wrong.

Also I am unsure if the REV letter is critical (mine seems to be an 'E' after peeling off the green sticker).

Any help and guidance is greatly appreciated.

Tim