Dear GraemeQ
A new RCM is available via FCPeuro.com here in US for $164. usd. Check their site https://www.fcpeuro.com/products/mer...lay-1705450305.
You can cross reference MB SLK320 parts for xfire use. Maybe you can locate the same SLK320 part for less at a local MB supplier in NZ or have someone in the forum ship one to you unless your customs will open the package.
Just a thought.
Cheers