In thinking about the timeline after posting... I gave the year 1969 only because of the position of David's address in my notebook, not because of any documen

In thinking about the timeline after posting... I gave the year 1969 only because of the position of David's address in my notebook, not because of any documentation containing a date. Based on my work at the time it is entirely possible that the visit occurred in 1970 or even later. I mention this to address the possibility that the year 1969 does not align with other elements of the story.