Hi there,
Unfortunately as per our rules we can't give out Engineer manuals to non-trade members, for obvious security reasons.
If you don't have evidence the alarm has been recently serviced, I would suggest getting a local firm in to do a full service
and most would be able to accommodate your additional work at the same time, depending on the actual work involved.
Sorry if this is not the answer you're looking for, but makes good sense from a security point of view.