FUJITSU/CYPRESS MB91F467C not programmable

Hi friends of microcontrollers,

due to EOL of Fujitsu/Cypress MB91F467Cxxx we have the need grabbing 
last items worldwide to maintain some industrial controllers.

Lastly we got some of them from different suppliers, all marked with an 
extra number (e.g. 944 or 752). Does anyone know the meanings of these 
extra markings? Main problems of the marked chips: Not programmable with 
original flash tools, so we had to trash them after desoldering! A hard 
decision for 100 and more items at 35 USD each ...

Any helpful hints are welcome

Thanks
Peter