Do the Huygens critical edition and Spinoza's Letter 32 verbatim support the 'Spinoza's dish still scratch-free in 1687' claim?

claim-spinoza-grinding-dish-outlived-him-in-huygens-hands rests on a Tier-2 scholarship blog (kvond.wordpress.com) that quotes the primary correspondence — Spinoza's Letter 32 (Nov. 1665) and Constantijn Huygens Jr.'s 1687 notes drawn from the Oeuvres Complètes de Christiaan Huygens (OCCH) critical edition — rather than the primaries read directly. The claim is surprising and load-bearing (a specific ground dish still outperforming rivals a decade after its maker's death), which the sourcing floor says should escalate toward a Tier 1-2 primary even though a Tier-2 secondary technically clears the historical-claim floor.

Why it matters

This is the durable-craft half of the capture's trade-secrecy bridge and the cleanest single illustration in the vault that tacit knowledge can live in a physical object, not just in years of practice. Confirming the two quotes verbatim against the primaries would let the note move off seedling and be quoted safely in a draft.

What would answer it

• The exact text of Spinoza's Letter 32 (to Henry Oldenburg, 20 Nov. 1665) — confirm the "polished by a free hand is safer and better than any machine" wording (in translation, and ideally the Latin/Dutch original).
• The Constantijn Huygens Jr. 1687 passage in the OCCH critical edition — confirm the "in the dish of Spinoza's... without once taking it from the dish... so that I had no scratches" quotation and its date.
• Corroboration that the Huygens family acquired Spinoza's grinding equipment at the November 1677 estate auction (the Haarlemse Courant advertisement, and Wim Klever's scholarship cited by the blog).

Candidate next moves

Locate the OCCH volumes online (the edition is public domain) and Oldenburg correspondence; treat Wim Klever's papers on Spinoza's instrument-making as the bridge to the primary archive.