The problem with these stats, Ctrian, is that all aircraft you list for 1941 were paid for by the UK Govt and not lend lease, and I suspect even the figures for Apr 42 included paid-for rather than LL assets. As for the Buffalo sqn in India in Apr 42 it consisted of 5 aircraft, the rest having been lost in the defence of Burma - but they were all bought and paid for using gold reserves. Also, the stalling of the Japanese offensive had less to do with defensive forces in India and more to do with geography - getting to western Burma already hugely extended Japan's supply lines and they had no means to continue the offensive into India proper.
Excuse me for using wikipedia but : ''It was signed into law on March 11, 1941, a year and a half after the outbreak of the European war in September 1939, but nine months before the U.S. entrance into the war in December 1941''.
How can aircraft in '42 in N.Africa and Far East be bought and paid for by the Brits?
Regarding your second post that's my entire argument that Britain was simply unable to continue the war without active US involvement one part of which was LL.