My Axis has two numbers on the bb shell. Have you only got one? I don't have any later numbers to compare. Sure it is definitely a DiamondBack?
I've got numbers from two frames starting H7J, they are both Fastrax.
This is a 1997 American market Axis. A couple have turned up. They were built by Hodaka, rather than the 'U' frame numbered examples. It looks like they were also manufactured out of Ritchey Logic tubing, rather then True Temper TT-Lite.