If I do try those files, will the immob info and VIN be wrong for my car? Just checking, as I don't want to compound my problem further.

The 2 files I posted are your first file modified through the avdi dump tool.  I just set the mileage to 0 and 1 in each file.  Your immo data was not touched.  The basic file structure and size looks right at a quick glance.

I've been able to fix a few clusters where the mileage showed 999999 just by correcting the eeprom.  I haven't needed to rewrite the mcu flash section yet and I don't think I have a way to do it.  From what I've read the display reads 999999 if the mileage and checksum don't match up.  Vagtacho clones don't correctly fix the file on later clusters.  The avdi dump tool writes the mileage blocks to all the same number as you noted but it also changes a couple bytes further down in the file,  maybe a checksum of some sort?  I'm not an expert.  I would've thought that the inverted mileage was written so that the value for the checksum would add up correctly but it doesn't appear that way.  Keep in mind I have a very basic understanding of checksums.

As for the mileage blocks all being set to the same value that is normal.  If you update the mileage with vcds and read the eeprom it shows the same pattern of all the same values instead of incremented by 2.  Also for whatever reason setting it to 0 didn't work on 1 cluster but has worked on others.  On the cluster that didn't work on 0km, 1km did work.  So I supplied both files.  If it works out then you can just adapt the mileage with vcds and you should be fine.

Here is a interesting writeup regarding faulti dash because of cold winter days.
http://www.motor-talk.de/forum/kombiinstrument-tacho-totalausfal-l-selber-reparieren-diy-t2597323.html

log story short: if your dodgy dials were replaced but you have still problems its maybe useful to replace this chip

http://www.codecard.lt/electronics/2j74y/mc68hc908az60-2j74y-processor-already-programmed-with-software-you-need/prod_127.html

Some how I uploaded the wrong file in the first place, so please ignore my previous post.

I'm now failing in extraing the eeprom using vag commander, whilst attempt a read using the direct setting not tt, the cluster seems to reset and vag commander then crashes. The cluster is in a timer that can be view in VCDS on channel 24 of the cluster, it seems to count down from 19, but takes about a minute per digit.

I need to pull the full eeprom again somehow, any tips?

intrigued to find out if this was sorted as i have a tt marelli dash i'd like zero'd ish / 500 miles to match the new/replacement BT engine.

Vagtacho seems to read it ok as a post 2000 file, no option to write back over obd

Hi,

can anybody assist me in finding the skc out of this full dump?

couldt find any info one the net so far

I agree with jase, looks like 1106.  Usually located in two bytes before immobilizer serial number, just need to convert to decimal.