Acorn is the model, Shorroks the manufacturer. I installed 100s of them. A firm called Security Equipment Sales sold them (It was actually part of Shorroks). Quite a good 2 zone control panel in its day . Made of steel and you needed the key to open it. Logic gate inputs and and had a nice little input filter on the zones of about 0.8 seconds to change state if I remember correctly, that really cut down on false alarms from poor wiring connections. Designed for domestic properties but was useful for small shops and offices too.
