Claiming rebuild cost - anyone been successful?

[BrettMRC]

Fairly soon I will be asking Company A to stump up the costs of an engine rebuild caused by their incompetence.
Company A confirmed that they would not be able to do this work themselves, and frankly I doubt I'd let them loose on a skateboard now anyway.

Based on this Company B are doing the strip and rebuild.

The legal cover on the vehicle insurance have said they will support us with this claim if needs be.

Has anyone on here successfully reclaimed the costs in a similar situation?

Thanks