how much I should reasonably expect to be written down and in interest repayments on a mortgage in 2008 of EUR200k.
A) Calculating the overcharge
They will do two different calculations, and pay you the higher amount.
The FSPO calculation
The writedown will be €24k - 12% of €200k
Interest on this c. €12k ( Higher than usual as you broke out so early)
Total redress: €36k - or 18% of €200k
I see that this is close enough to Jomo's figure 18% of €178k = €32k and he got €31k.
The Central Bank calculation
They will look at what interest you actually paid.
Then what you would have paid on a tracker of about 1.5%
Then they work out the difference.
I don't think that there will be much in it.
B) Calculating the compensation
The Central Bank scheme was an automatic payment of 15% of the overcharge - so about €4,500
You get to keep this. But you can appeal to the Appeals Panel or the Ombudsman for more if you have been particularly inconvenienced.
C) You will be on a tracker of 1.5% from now until the end of your mortgage