Hi, Foam Replacement set are ridiculously cheap compared to B&O prices standards, so don' bother with serial numbers: open the speakers and if black, order the parts. The most complicated step is to find a dealer who sells after sales parts (meaning "not only interested in selling a too much expensive TV set to you). But providing part number and with a sweet chit-chat talking it's in the possible domain! Alternativly they are blueprints available to download for silver and gold members, to make your own pads. From there, many DIY topics on Beoworld about the "how to". Good luck.

Here in the US, I'd be happy to have any dealer closer than 700 miles - the distance to my current closest dealer -  or even better, a service center within driving distance! It's not like I live in a small city, but i guess the market just isn't here any longer 😕 I may have to order some foam and give this a shot... as usual, I should have thought of this *before* I gave them to my son... when they were simply collecting dust in my office.