coin-plan

Coin Collection Planning Methodology

When to use

• User uploads a Numista CSV export and wants gap analysis
• User asks "what am I missing from [series]"
• User wants to start a new series and needs the complete list
• User asks for coin fair shopping list or buying priorities
• User wants series suggestions based on existing collection patterns

Step 1: Parse Numista Export

The CSV columns that matter:

Country, Issuer, Ruling authority, Title, Type, Face value,
Reference, N# number, Gregorian year, Mintmark, Composition,
Grade, Collection, Comment

Key parsing patterns:

Design name extraction — names are in parentheses after portrait info:

import re
m = re.search(r'\((.*?)\)', title)
design_name = m.group(1) if m else title

For multi-portrait series (UK) — strip portrait prefix:

m = re.search(r'portrait;\s*(.+?)\)', title)

Filter non-circulation (if the collector excludes silver/gold proofs):

if 'silver' in comp.lower() and 'clad' not in comp.lower():
    continue  # skip pure silver

Dedup by (design, year, mint) — same design+year+mint = one entry, track count.

Step 2: Build Series Master List

Research sources (in order of reliability):

1. Numista catalogue pages — authoritative for KM#, dates, compositions
2. Web search for series overviews (PCGS, NGC articles, Baidu Baike for China)
3. Cross-reference user's Numista export N# numbers against known series

Series identification from collection patterns:

• Look at Type field: "Circulating commemorative" vs "Standard circulation"
• Group by denomination + composition to identify series
• Check year ranges for continuous sequences (gaps = missing coins)

Common series structures:

Country	Series	Denomination	Format	Years
US	50 State Quarters	25c	Cu-Ni clad	1999-2008
US	DC & Territories	25c	Cu-Ni clad	2009
US	America the Beautiful	25c	Cu-Ni clad	2010-2021
US	American Women	25c	Cu-Ni clad	2022-2025
UK	Round Pound Emblems	£1	Ni-Brass	1983-2015
UK	12-Sided Pound	£1	Bimetallic	2016-present
China	Lunar Zodiac	10 Yuan	Bimetallic	2015-2026
China	World Cultural Heritage	5 Yuan	Brass	2002-2006
China	World Heritage Mountains	5 Yuan	Brass (square)	2019-present
China	Peking Opera	5 Yuan	Brass	2023-2027
China	National Parks	10 Yuan	Bimetallic	2023-present
China	Calligraphy "He"	5 Yuan	Brass	2013-2022
China	Famous Sights Taiwan	5 Yuan	Brass	2003-2005
China	Red Book Animals	5 Yuan	Copper	1995-1998
India	Princely States	Various	Various	Various

Step 3: Gap Analysis

Build collected set:

collected = {}  # (design_name, year) -> set of mints or count

Cross-reference against master:

for year, name in master_list:
    if (name, year) in collected:
        status = "HAVE"
    else:
        status = "NEED"

For mint-variant series (US quarters):

Track P and D separately. Show both as columns — bold if collected, light grey if not.

For single-variant series (UK pounds, China):

Simple tick/no-tick checkbox.

Step 4: Suggest New Series

When user asks "what else should I collect", apply these filters:

Compatibility criteria:

1. Same denomination/format as existing collection (if user collects 5 Yuan brass, suggest other 5 Yuan brass series)
2. Same price range — circulating commemoratives, not proofs/bullion
3. Completable — finite series with known total count
4. Available — coins still obtainable from dealers at reasonable prices
5. Thematic match — the collector's stated interests (see Collector profile below)

Priority ranking for suggestions:

• High: Same format, same country, <20 coins, cheap, available
• Medium: Same country, different format but affordable
• Low: Different country but thematic match

Step 5: Shopping List

For coin fairs:

• Prioritize by geography (local fairs stock local and regional coins best, e.g. a fair in South India is the best place for South Indian princely states)
• Group by priority: HIGH (likely present), MEDIUM (ask dealers), SPECIALIST (dedicated dealers only)
• Include specific denomination names dealers would recognize
• Add empty checkboxes for ticking off at the fair

For online buying:

• Note which coins are common circulation (cheap) vs commemorative (premium)
• Flag any coins that are scarce or have high collector demand

Step 6: Output

Generate output using the a5-coin skill for binder-ready PDFs, or Excel with openpyxl for digital tracking.

Excel output columns:

S.No, Official Name, Year, Denomination, Current State/Country, Region, British Era (for India), In Collection?, Coins Owned, Priority

PDF output:

Use a5-coin skill — Carlito font, grayscale, 6-hole punch, continuous flow layout.

Collector profile (fill in your own)

Keep this section short and update it as the collection changes. The skill uses it for suggestions and shopping lists.

• Numista username:
• Approximate collection size:
• Active sub-collections: <e.g. British Round Pounds, Chinese Lunar Zodiac, US Quarters>
• Printing: <colour / grayscale>, binder: <A5 Filofax / other>
• Home city (for coin fair lists):
• Exclusions: <e.g. no silver/gold proofs>

Known gaps (date)

• : /, missing