AP1 Irons

I noticed the new prototype irons have 712 series to designate the model year. If a person purchased AP1 Irons in May 2011, what series number should be stamped on the club?

The current ones in stores should be stamped 710.  if they are not stamped 710 they are the original AP1 from before. 

Bob B
I noticed the new prototype irons have 712 series to designate the model year. If a person purchased AP1 Irons in May 2011, what series number should be stamped on the club?
I received sleeve of Titleist balls to test.  I normally use Pro V1 & was wondering what the test balls were??  I also have tried the new NXT Tour S balls & liked them.