1900 American Eagle take down lever

According to books that I've read, the last two digits of the serial number were stamped on the right hand side of the take down spindle. These where stamped on 1900 models up to serial number somewere around 7000. After that they supposedly stoped.

I have a 1900 American Eagle with a serial number of 84xx, with the last two digits stamped on the right hand side. The number stamps match the other numbers on the gun.

Has anyone else come across this or seen one.

Thanks,

Bob