I do not mind taking the dash cluster to be adjusted however have not found anyone that knows what they are doing with it.
The error has been constant for a decade+, and is in RPM as well, (needle vs ecutalk) so I do not think it is the sender, and I do not see how it can be in the cluster firmware, so that means it is in the little units behind the two needles. If they can be adjusted for error, thats great. can they? I cant find any evidence of that service, with lots of google effort.
edit: asking humphery instruments in the gong what they reckon. will update