Thornycroft mysterious box

[Rafal]

Hi, I bought boat with twin Thornycroft T238. Lower helm control panels are connected to blue box, which is connected to dial with lights. Positive ftom box goes to tacho plus, three negatives to tacho minus and W12, two extra to other panel tacho. Does someone know what the purpose is, please?

 

[Mr Googler]

Engine Rev synchroniser display?

 

[Rafal]

Thank you for answer. At least I know what to look for.