Gotta love the weekend markets..
Had a look through one of the stalls today and noticed this..
Got it home and opened the back.. Luckily it was somewhere that I didn't lose these..

Onto the interweb.. Asked some questions.. Looked at the tech sheets for the H601.. The 'clip' goes here..

Not sure about the spring.. but questions answered by a member of another forum.. The spring is part of the alarm and has to touch the speaker on the caseback.. found the hole it belonged in.. inserted a new battery.. and voila..

All operational again..