The spiorad.net Mamluk-deck reconstruction site's account of the coins-to-polo-sticks resemblance is its own inference, not a citation to Mayer or Dummett, and traces back to the same uncited Wikipedia sentence

history-of-gamesplaying-cardsetymologysourcing-verification

entity-ulrich-kaltenborn ("trzes"), a specialist collector who has built his own reconstruction of the Topkapi Mamluk deck and engages directly with both L.A. Mayer's and Michael Dummett & Kamal Abu-Deeb's academic texts on the deck's structure, offers his own account of why the Chinese coin-suit symbol was reinterpreted as a polo-stick on reaching the Islamic world. But he frames it explicitly as his own reading rather than a citation to either academic source: "apparently," "probably," and — for the specific resemblance reasoning — a parenthetical "(see Wikipedia)" rather than a reference to Mayer or Dummett.

This matters because spiorad.net is otherwise a genuine independent Tier 2 corroboration of the Mamluk deck's structure (suit names, the polo association of the polo-stick suit). But on the one point the vault most needs sourced — the mechanism by which the coin suit became a polo-stick suit — the specialist source that most directly engages Mayer and Dummett's texts does not draw on them for this claim. It points back to the same uncited Wikipedia sentence the vault's own claim traces to.