Audio 10 cd

Sorry if this duplicates as ive posted but it seems to have vanished.
Anyway i used to have a merc c180 L reg and the original owner upgraded the stereo and i never got the code. The merc died a death during a high speed smash and i kept the radio as it sounded nice, now i have another car i would like to put it in! Ive taken the unit to two unlockers and both of them have given me different information first off they have told me its a blaupunkt and given an incorrect code, and then another shop told me its an alpine and yep a incorrect code.
Please help! id love to get this up and running again.

Heres whats on the unit (merc symbol) A170 820 03 86
Serial number :AL291020408547B

Elektron1234

Im sorry mate i dont have the VIN number as the car was destroyed,also the stereo was an upgrade for it. So no VIN im afraid

Thanks elektron1234

Can anybody else please??????