Kind of agree, with all the above. Mowbrays are your best bet and being Otaki, they are not that far from Whanganui.
Before you do though - answer these questions.
1. Is this collection mostly consisting of the following items?
1965 and 1967 Proof sets in plastic packaging and cardboard outers - Pink, Green and Blue Labels.?
10/- and £1 banknotes in any condition other than perfectly flat and new?
Coins consiting mostly of pennies/halfpennies and any 1947 or later coins in less than perfect condition?
Perfect condition These are not perfect condition and worth only metal value.
1967 and 1969/70/74 slabbed $1 coins - also 1953 crown and 1953 bronze medal for the queen given out to every school child?
Coins in bags that are all mixed together including all the above and 1c - 50c of NZ from 1967 to 2004?
$1 and $2 banknotes from the 1980s (They always are) even in perfect condition?
British pennies and halfpence from as far back as 1797, yet all worn flat or heavily worn?
Modern world coins, mostly of base metals like copper. brass, nickel, aluminium, etc
If your answer is yes to any of the above, generally dealers WILL NOT be interested in them and such items have minimal value. figure 10c per penny and cupronickel coin (Halfcrown/50c down to 5c/3d) - give them to a child or a doveshop or something.
HOWEVER!
If the collection contains any of the following.
Any coin with silver in it including New Zealand coins 1946 and earlier, 3d and up only NO PENNIES OR HALFPENCE.
British coins before 1947 (Not including 1947 dated coins, 1946 and earlier) and again silver coins only, no Bronze or copper
Any gold coin - sovereigns etc - not the joke shield guineas that say “For the memory of the good times” its a worthless brass token.
Banknotes from NZ including better grade notes £5 and up, NZ $5 and up
Coins that are very old (Like pre 1800s that are NOT copper or base metal like aluminium)
Old banknotes - except German inflation banknotes (Have gothic lettering and always dated 1922 or 1923 = worthless)
Then contact the dealers, hope this may help.
Other dealers include John and Peter Eccles (Auckland and Wellington) and Howard Mitchell Auckland - details online.
I love coins. Especially silver, gold and anything really old.
Member of the Royal Numismatic Society of New Zealand and the Auckland Numismatic Society