The reason for replacing the bunks was that they were 10cm too short like Greys and I was not happy they did not support the transom as I want to keep the Elling on the trailer permanently also when towing I felt more happy the transom supported with the outboard on.
Below is the start trying to get the old bunks off, the bolt were so rusty that the only way to get them off was to cut the ends away so to cut through the bolts with a hacksaw, it was a lot more work than I expected but got them off in the end.