Unless the machine was clapped out, there should not have been any need to replace valve bodies. There has not been a recall on the pressurestat/tempstat in Australia. Was there on in NZ?
A small batch of Maters were replaced here under warranty- if, and only if a fault occured. Relay? Which? The only relay is on the control board. Is it a DB?
At 2 years- assuming scale was ok and good hygiene, a service should be little more than attending to leaks and squeaks along with a group seal and shower screen.
Unless the machine was a shocker, it sounds like an interesting call to me.* :-?