If tho motor is still not replaced, Norway is relatively near you, so maybe you could find something cheaper here:
https://finndel.no/bildeler.aspx?bk=354705&dk=0137

I think the simplest and fairly reliable way to measure SOH is to calculate the data measured and displayed by the car. Please use this Google sheet , choose 1 of 4 green tables on the left regarding consumption display, enter the data in 4 white cells and the table should calculate the SOH value. A...