Here's some info to be going on with.
The headstone for the 1949 burial in Mangatera Cemetery in Dannevirke reads:
Great War Veteran
23028
Rfm A.H McLEAN, Rifle Brigade
Died 18 March 1949
Aged 59 years
The burial register reads:
A.H McLEAN
Buried 20 Mar 1949
Source: NZSG Cemetery Fiche F04.12
Entry 3320
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The WW1 Service Personnel CD matches the regimental number to:
Surname: MCLEAN
Given Name: Allan Hector
Regimental Number: 23028
Rank: Rifleman
Next of Kin Title: Miss A
Next of Kin Surname: MCLEAN
Next of Kin Relationship: Sister
Next of Kin Address: Runanga Greymouth
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The electoral roll preceeding the burial is 1943.
Dannevirke is in the Pahiatua electorate.
There are listings for:
McLEAN, Allan Hector - 12 Stanley Street, Dannevirke - Labourer
McLEAN, Florence Molly - 12 Stanley Street, Dannevirke - Married
McLEAN, Allan Hector (Jnr), Rifle Range Road, Woodville
McLEAN, Hazel Amelia Mary, Rifle Range Road, Woodville - Married
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The electoral roll following the burial is 1949.
Dannevirke is still in the Pahiatua electorate.
There are listings for:
McLEAN, Florence Molly - 12 Stanley Street, Dannevirke - Widow
McLEAN, Allan Hector (Jnr), Rifle Range Road, Woodville - Labourer
McLEAN, Hazel Amelia Mary, Rifle Range Road, Woodville - Married
There is no listing for Allan Hector McLEAN
There is a listing for a Margaret MACLEAN, a widow living at 12 Stanley Street, Dannevirke
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EDIT: The following three cremation record links I gave seem to no longer be linking correctly. A ghost in the machine, perhaps. Here is the cemetery search page instead.
http://www.pncc.govt.nz/ServicesAndFacilities/OnlineServices/CemeteryAndCremationSearch.aspx
There is a 1960 record of cremation for Florence Molly McLEAN at Kelvin Grove Cemetery, Palmerston North.
Cremation Record 1
There are also records of cremations for Allan Hector McLEAN in 1970 and Hazel Amelia Mary McLEAN in 1988
Cremation Record 2 and Cremation Record 3
Both Allan and Hazel are listed as having a "Book of Memories".
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An assumption made is that Allan Hector and Allan Hector (Jnr) are father and son. Not too sure of that as Allan Jnr married Hazel Amelia Mary FRANKLIN in 1932 whereas Allan (Senior) married Florence McCOLGAN or WATT four years later in 1936. And I can't find a record of birth. (AFTER THOUGHT - Although that's easily solved by requesting Allan (Senior) army service record be digitised. It will/should mention Allan Jnr as he was born in 1912)
And although the cremation records of Allan (Jnr) and Hazel Amelia list different addresses, the 1970 electoral roll for Palmerston North has them both living at the same address - 385 Botanical Road, Palmerston North. Allan (Jnr) is listed as a factory worker. Hazel Amelia is listed as married. Unfortunately there are no other McLean's listed at that address.
It's all guesswork. Caveat emptor, cave cane etc
Regards
Beg