V12twinturbo

Hi to All, I’ve been a non-registered reader since August, when we bought a 2011 Fabia 1.2 TSI manual for my son as his first car. It needed a bit of work, and I’ve now created an account to ask a question. One of the rear shocks had failed (the other one was replaced by the previous owner earlier this year to pass the MOT). While replacing the it, same as in @GrumpyBob 's thread, we noticed a rust hole in the rear axle beam near the lower shock mounting point. After some digging I've found out that there are two OE part numbers - one for drum brakes and another one for disk brakes. Are the two versions physically different, meaning they won’t fit each other or just some bits and pieces that can be swapped? I assume there must be a reason for the different part numbers, but can’t spot any differences in the pictures. The reason I’m asking is that some aftermarket manufacturers list both OE part numbers as compatible with the same axle beam (this one for example), while others specifically list only the disc-brake version and don’t seem to offer a separate version for drum brakes (this Diederichs one I'd really want to buy if it fits) Appreciate any advice or information.