I need information regarding the A6M3 Model 22a Zero (with improved
long-barrel cannons), which I have not been able to find elsewhere.

* What was the month/year that this specific model (22a) of the Zero
became operational? I need to know whether it entered service before
or after 1942.

* Did the Model 22a operate extensively off of carriers, or was it
primarily a land-based fighter, like the A6M3 Model 32?

* How many Model 22a's were built (specifically the 22a version, not
the total number of Model 22's)?

* I have read one source that said that the A6M3 Model 22 was the
longest-ranged of all the Zero variants. Is this correct?