[CR]Chain with <65> on links?

(Example: Events:Cirque du Cyclisme:2002)

Date: Sun, 30 Dec 2007 20:57:11 -0500
From: "Harvey Sachs" <hmsachs@verizon.net>
To: Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: [CR]Chain with <65> on links?

Wise peers with long experience: Tonight I pulled out of the bag a fine-looking chain, 1/2x1/8" (non-derailleur). Each outer plate is marked with a "65" inside a diamond. No other brand mark.

anyone know what it is? Is it old enough for use on an early 50s bike?

thanks
harvey sachs
mcLean va