It should be, one of the first months of the original IIC+ You might still want more info about it to be safe. you can always pull the chassis and look at the lead between the two master volume pots... Master 1 and Lead Master. If they are in series it's a IIC. if it passes visual inspection and the loop test, and there is no writing on the chassis like IIC-->IIC+ with a date then you have an original. you can also call and talk to mike b. and see if he has any info about that one or a return auth history. Is this the one that you sent in to Mesa? or a new one?
scott