Mess of wiring, tape covering joints, 10 zones on 8 zone panel and seems to have no tampers.
Burn marks around R69, D1, D3 and D13 indicate the panels PSU has probably been overloaded and the components will be tired.
If it was a decent system in good order it would be worth looking after, but I'd rip it out myself TBH.
I reckon tamper circuit has a fault hence bypassed instead fixed
All this flaffing around and going in circles what's the point? Get services or fixed.or DIY it which looks as if it's been down that route with tamper bridged
QFA
If you do wish to keep it, expect to pay around £200-£300 to have it all re tested and commissioned.
you may get a cheaper deal if you are going to put it on an annual service contract, (this would also give you access to emergency call out facility incase It’s goes pop)