Hi kimmit
The following is the info mentioned earlier, which I was going to add here, mainly as a last resort if other methods of searching didn't yield a result.
Not all cemeteries in NZ have searchable databases available online ... and there are still cemeteries connected to churches whose records are also not online but may be available via the particular demonination's archive (usually a fee is involved or you need to personally visit the archive to obtain information).
* * I suggest you contact the Christchurch Libraries website and use their "ask a librarian" facility.
They have a unique resource > a Card Index system of transcripts of Church Registers of Baptisms, Marriages and some Deaths/Burials, covering wider Canterbury and spanning many years. The Anglican (C of E) registers are well represented.
Explained here >
https://my.christchurchcitylibraries.com/family-history/church-registers/As you have evidence from other sources, of the SKUDDER burials at Rangiora, you need only supply those details and ask if you could have them do a look-up in the card index system for you.
[Maybe give them that variant spelling "SCUDDER" also.]
Link to Christchurch Libraries "ask a librarian" >
https://my.christchurchcitylibraries.com/contact-us/And do let us know how you get on with this.
~ Lu