Corsa B Binnacle

[GC8]

Does anyone know if a binnacle which incorporates a tacho can be easily adapted to fit a vehicle which only had a speedometer originally? I have to replace the speedometer on a poverty spec 1,200cc model and a tacho would be useful, as it screams like a banshee at anything over 3,000rpm, making any kind of judgement difficult.

I realise that it can be completely inpractical on some vehicles, whilst its pretty easy on others, with a coil wire and a small amount of bodging. I know less than nothing about cars like this: honestly...