ref: American Federation of Musicians (AFM) Standard Recording Contract between Spencer Dryden [leader, signed] and Columbia Records [employer, signed], dated August 18, 1975, for sessions at Record Plant, Sausalito, CA, August 1, 1975, AFM6 San Francisco Sessions Dataset, 1967-1972. The union paperwork listed two session times, one set of songs. So we end up with this event and a seeming duplicate, but what can you do?
ref: Jerome John Garcia covered wages and pension contribution statement from American Federation of Musicians and Employer's Pension Welfare Fund (AFM & EPW Fund) (1975), ca. 1976, Grateful Dead Archive, Special Collections, UC Santa Cruz, MS.332 ser.2 (preliminary accrual), box 3.