Thumbs up [Q] U8860 (Honor) wiped my Serial -> mutating MAC

Hello out there,
I need some help from specialists.
After a full erase of system-partitions my U8860 lost its serial number. Now I get a new (generic) MAC every boot. In some other posts I noticed, that a NULL-Serial causes such a generic MAC - what a pitty: my wlan@work has a MAC-filter, so my device could not connect anymore.
Does anyone has an idea, to write the serial back to the device?

Thank you for reading!