L5 News ·
L5 Provenance
A New Era of Provenance Search
Our retrained model is live — and it’s the sharpest we’ve ever built.
Over the last few months, you ran tens of thousands of provenance searches on L5. Every confirmed match and every near miss became training data. Today we’re launching the payoff: a completely retrained provenance model.
It’s roughly 3× better at finding matches than the model it replaces — and because it’s so much more efficient, we’ve been able to double the index behind it, now over 4.5 million coins across 4,500+ auction catalogs, all searchable by photo. It’s also about 5× faster, returning a typical search in around 2 seconds instead of 10.
New: 72 catalogs from CNG
We’re thrilled to have received permission from Classical Numismatic Group (CNG) to bring 72 of their landmark sales from 1992–2010 into the provenance index — the modern reference standard for ancient coins, now searchable alongside a century of classic European auctions.
Discoveries Across the Eras
Real coins L5 members photographed and traced back to earlier auction appearances — your photo, then the match.
Before 1940
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Rollin & Feuardent
Paris
1887
found by @redfox21
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Rollin & Feuardent
Comte du Chastel Coll.
1889
found by @redfox21
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Sotheby’s
Carfrae Collection
1894
found by @All_things_Thracian
1940 – 1959
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Glendining
London
1941
found by @redfox21
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Hess, Lucerne
Laughlin Collection
1943
found by @redfox21
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P. & P. Santamaria
Rome
1949
found by @redfox21
1960 – 1989
→
Jean Vinchon
Paris
1961
found by @redfox21
→
Glendining
London
1963
found by @All_things_Thracian
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Jacques Schulman
Amsterdam
1966
found by @redfox21
1990 – 1999
→
Numismatic Fine Arts
Sale XXIV
1990
found by @redfox21
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Superior Galleries
Maltiel-Gerstenfeld
1990
found by @redfox21
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Gorny & Mosch
Sale 50, Munich
1990
found by @giga-ancients
2000 & Later
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Classical Numismatic Group
Review XXV
2000
found by the L5 team
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Harlan J. Berk
117th Buy or Bid
2000
found by @redfox21
→
The New York Sale
Auction III
2000
found by @redfox21
How to get the best results
A few small things make a big difference. Photograph both sides of your coin, tap Remove background to clean and center each side, and check that the split between obverse and reverse is clean before you search.
When the results come back, know what you are looking at. The search ranks millions of coins by how similar they look, so your list will always include coins that are not yours, sometimes even one from a different era. That is normal, and it is not a sign the search failed. Your job is to scan the list for the single coin that is genuinely yours, and the true match is not always at the top.
A note on coverage: the index spans auction catalogs from the 1880s through 2010. We don’t yet index sales after 2010 — so if your search comes up empty, the coin’s last recorded appearance may simply be more recent than our range.
Thank you to the L5 community. Members have already contributed hundreds of catalog scans to the archive — every one makes the whole index stronger.
We’re especially looking for high-quality scans from M&M Basel (Münzen und Medaillen), Tkalec, Tradart, and Lanz. If you have catalogs from these houses and would like to contribute, just reply to this email — we’d be grateful.
L5 — ancient-coin auctions, a dealer marketplace, and the largest free coin-provenance search.
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