Parts books for the most part, are available on the RPS page of the REMLR website, user handbooks i've only seen for the 110 range of vehicles, not the series 2 or 3. The only exception that I have seen to date is for the Wrecker variant of the series 2 and 2a which mostly details the use of that specific equipment.
I do have a copy of what is in essence a drivers handbook issued to soldiers on their drivers course detailing a range of information, but i've not worked out a good way to digitise that as yet, and it does not relate to a specific vehicle, but more in general.