How to reset the alarm without knowing any code or info about it

[Samsg30]

Hi,
We moved into a new home where there's already a security alarm installed. However the previous owner had died and there's no info whatsoever regarding the alarm so wondering how can we reset the code to make it work again. Attached are the two pictures of the alarm. I cannot see any other sticker showing model number etc.
I can do some DIY so don't mind opening alarm and tinkering with it if necessary to make it work.

THanks

 

[Rodders53]

Google Lens Image Search leads me to believe it may be a Friedland SL5 alarm system.

https://www.manualslib.com/manual/864500/Response-Sl5.html might help if that is so?

 

[secureiam]

Plenty of manuals about online