HP4000M Serial Number moves!!

[Stryderusa]

Hello, I am in the process of performing an inventory audit of swithces and we have several dozen of the old ProCurve 4000M switches. I have located the chassis serial number on the rear of the units in stock and have been recording these for our inventory audit. However, I have found some duplicate serial numbers when I Telnet into the management modules of active switches. I suspect that the management modules may have been swapped in the past with the chasses which are now in stock, however I cannot believe that the serial numbers are hard-coded into the management module instead of the backplane board? If this is the case, is there a way to update the serial number in management modules to match the chassis UPC serial numbers attached to the outside of the chassis, other than having to move or create new external UPC decals? Any insight on this would be appreciated. Thanks