A quick note concerning Marklin’s line of BR 101’s. I just received the older 88687 which is a member of the Bayer series of class 101’s, it arrived with one buffer off.  Sooner or later you might come across this and maybe the first inclination is to glue it back on, but please don’t! The original and brilliant design included a clip system without any glue entering the mix. The black part that holds the buffers works also as a clip to hold the LED’s in place, two prongs on the black buffer part engage with tiny holes in shell and wow its back together again. It is of course part of the natural occurrence with Z to have something come loose, but rarely if ever is this due to broken or defective parts so stay away from the glue unless the loco dropped to the concrete floor and cracked, in this case 5 minute epoxy is the way to go.