Hi Wiking,
According to italian wiki there would have been a total of 75 BR-20M, 50 CR-42 and 45 G-50. Obviously they would have increased the pressure on Malta, though not sure what was the situation in October-November 1940, and whether the extra 150 aicraft would have ben the proverbial straw for the british defences. But imo, it would be all hollow without actually carrying out a landing on Malta, however risky and heavy the losses, if they take Malta it's still hugely beneficial in the long term, avoiding most or all the air and naval losses from 1941-1943 caused by it being in british hands.
PS: The other option being to use them in Greece, if they still proceed with that unfortunate adventure. At least they could have had more of an impact than they had over Britain.