British Pathé has a newsreel of Weymouth 1968, lasting 1 minute, 6 seconds. Unfortunately there’s no sound, but the video is interesting nevertheless.
There is also one additional game, Keane – Rantalainen, round 9 (Ireland – Finland), not in the OlimpBase collection, from the Evening Herald of May 8, 1968. Not a classic, unfortunately: Rantalainen erred in the opening and Michael Keane recorded Ireland’s quickest win of the event.