Pre Ban Manufacturing dates for Cobray/Leinad

[therevenger]

I just picked up what I believed to be a pre ban cobray TM11 carbine, but unfortunately my FFL will not transfer it without proof that it is a pre ban rifle (I'm in one of those states). I contacted Cobray, but the guy was unwilling to provide me with any documentation as to the manufacturing date. The number begins with 94(year produced), but I haven't got anything that would suggest that it is in fact a pre sept 13. Is there any way I could acquire some kind of documentation regarding the serial number?