Here's a picture of the Apollo 6 optics during its post-recovery inspection; you can see the ablative panel and optics which had been removed from the spacecraft prior to display.

The scan quality of the Mission Report is rather poor, and I can't find S-68-3676 anywhere else on the Internet. If you know where I can obtain a better picture, please contact me.

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From p. 5.4-29 (p. 159 in the PDF) of Apollo 6 Mission Report
Extraction and cleanup by heroicrelics.

Here's a picture of the optics taken on the recovery ship:

A full-size crop from S68-27041