As per deadessays post
1970 Redated Tapes, "There’s no evidence the Dead played any show in San Diego that month, let alone a casual acoustic show." and "Since it’s evidently in a small club, the best candidates are the Matrix and Lion’s Share." and lastly "It’s in roughly the same time period, late July/early August". Extensive review of San Diego Free Press v01n19 (issue 19) (July 25, 1970 - August 5, 1970), p. 16, accessed via Underground Newspaper Collection microfilm, reel #24 indicates no evidence that this show was booked at Golden Hall.