Why is this now been rejected?
Most of the more recent Central Bank Collector issues are sets, either year sets, or theme sets, first issued in NZ in 1935, and every year since 1967. Proof sets and uncirculated sets.
Most of the sets, and ALL of the Proof sets only contain coins that are issued ONLY in that set, they are not available as separate items.
Your database needs to be updated to include these items.
You should include everything that was previously listed in Krause Catalogues, and all the updates from Greysheet.
This would make your platform more useful for those who are new to Numismatics, and be fully informative for all users, a lot of people just collect year sets.
How are they to find relevant resources, information on their collection?
No good looking at individual values, as that is not relevant to set values.
Bring it into the 21st Century.
It will be a lot of work, but it will keep your platform relevant and informative.
I have already advised on several items missing or required updates to your catalogue .
Keep updating to make it more user friendly and relevant.