The Apple Studio was renovated over a perod of 18 months reopening in September 1971. So there might have been some activity down in the basement at 3 Saville Row during the summer of 1969.
This website, Classic UK Recording Studios in the 60s & 70s http://www.philsbook.com/index.html
describes the following recorded at the Apple Studio:
The Beatles - Let it Be - 1969
Fanny - Fanny Hill - December 1971
Eulenspygel - Ausschuss - 1972
Mark Wirtz - Balloon - May 1072
Stealers Wheel - Stuck In The Middle With You.
George Harrison - Living In The Material World (Part)
Badfinger 3rd LP December 1974.
Tim Hardin - Painted Head.
Nazareth - Loud ‘n’ Proud (1 track))
John Howard - Kid In A Big World 1974http://www.philsbook.com/apple.html