Really ?
What other 30yr old constantly on electronic kit in your house have you still got ?
The sensors been dropped when the coving was added...
Many people only buy 8 core.... saves having lots of different reels & wiring in 6 when 7 pairs are needed....
you have my my deepest sympathy...
You need nothing better than a DVM - Voltage, Current, Resistance. voilà every measurement need for an alarm circuit
Throw it away & buy something less shite,
If I wanted to bodge your knacked old alarm to together-
Adjust stetsons to correct angle, check for indians (not you Al ? )
Assume tamper is a negtive loop,
Assume 12hr circuits are positive loops
At the controls place + voltage into one leg of an unused unlinked zone, if not closed try the other leg
Should it not work or the controls start smoking see underlined text or try - ?