The wheels and coupler really do make the model look very nice indeed.

I've never heard of an OBK coupler ... does it prevent buffer locking? It must be almost invisible from a normal viewing distance.

- Richard.

There is most definitely no protection against buffer locking. You need to be confident that anywhere one or both vehicles coupled with one or two of these go has curves that are not going to cause trouble. The recommendation is to use sprung buffers, but I have (probably through not having spent long enough shunting with these couplings) not yet had trouble on the (fairly short) vans fitted with unsprung ones.

Speaking of tight curves the photo attached shows a situation I think I have only ever previously seen on a model railway. I wonder if that explains the fact there is a partly dismantled coupling lying on the ballast. This is at ÖGEG, Lokpark Ampflwang (Austria).

I've worked up first versions of the front and rear guard irons in CAD, based on a copy of the general arrangement drawing in the Eisenbahn Journal special covering the BR 86, II/94 by Manfred Weisbrod and Horst J Obermayer (this can be bought online from the publishers as a digital download, or second hand from Ebay or Abebooks). The drawings looked promising enough to try out in brass. I cut and filed them from thin brass sheet. Here are some pictures showing them fitted. They need a little straightening and centring.

As I have drawn them, the guard irons don't line up with the cutouts for the front carrying wheels because Fleischmann made these up to allow the model to go around R1 radius curves. The real loco has bar frames (like North American steam locos) that run behind the top half of the wheels. Fleischmann's creativity is rather exposed by the finer flanges of the RP25 wheels fitted now. The mudguards are higher than they should be, too. I am pondering whether I can bring these down a bit. With no footplate they're a very characteristic feature of the BR86; checking sources shows they were not part of the original design and the first locos built didn't include them.