Oliver,
I cannot give you an exact date or serial number and nor can B&O because what happened was this:-
The PC2 hardware & software was introduced and it was a disaster and it took more than a year for the software to become approaching an acceptable product. Several new software versions came out, and during this period the hardware was seemlessly updated or so they thought, there was no statement to dealers saying there was an updated hardware box, it was just phased in with the "Type" number not changing and serial numbers not noted.
When software version 4.01 was released and during installation, the firmware of the PC2 was updated, however it failed for hundreds of users who did not have the updated hardware box, there was panic at B&O and there was hundreds of postings on the OLD Beoworld site about it. The reason for this panic was if you did the firmware update it made the PC2 box useless and you could not go back to the old version, it was effectively a "killer" piece of software. At that time any user who had this problem got their PC2 box replaced for free.
The name Beoport was a pure marketing change to bring it in line with other products, the product is 100% the same as PC2 (later version)
If you have a Beoport/PC2 hardware box and it needs a firmware update, then the installation software will do it automatically, no dealer involvement. If you purchased the product under the marketing name of Beoport, then you certainly have the latest version and if you can install and run any version including and after version 4.01 then you also have the latest hardware version.
The latest software version for Beoport is 4.80 recently released.