Throttle body taper boring

Is there anyone here/anyone know someone who can taper bore a B18c type R throttle body same as the spoon ones?

So not opening out the throat / changing butterfly size just taper boring the inlet side to 70mm down to the standard size.

I do know someone who could do it but I'm not sure whether he would need to make a jig first to mount it in his lathe in which case it's not really worth all the messing to do one TB

Any engineering firm with a lathe and independent 4 jaw chuck should sort you out. I've done a couple on my mates lathe. You could probably do a regular synced chuck grabbing the inside of the manifold side too. Find a local greasy engineering shop and take pound notes IMHO.