Dear Carlos,

Your question is a good one and needs time to answer!
The coupler itself is no problem but if you need the coupler holder which is attached to the car that is another story.
I have tried to find it on internet to no avail.
I will make another attempt over the weekend.
I have the same series of cars,a total of six coupled together 2 by 2.,Marklin 42021,great value for money!
Perhaps this gives a clue.

Is the coupling mechanism as attached to the car having a swiveling construction for sharp corners?
If yes,there should be a V shaped groove in the underside of the coaches.

Please do not dispair,help is on its way!

Paul.

Dears
Paul and Mike,
Thank you gentleman for your interest in helping me, but finally and after an exhaustive search on the net, I did come up with the Part Number of the coupler pocket for the Prussian passenger compartment double cars 4206, 4207, 4208 and 4209.
I did communicate with Märklin DE, but they did not answer my e-mails, so far!
I also tried the catalogs which I do have, on an intent to find out the part in need, and nothing no info on the coupler pockets or any other part beside the normal servicing parts.
Like Paul says the coupler itself is not the problem, I do have those.
Anyways at the moment I did localized these parts # 313940 and guess what, Walthers has these parts in stock, as per they're web page, I also found some on e-Bay, the problem was the unknown P/N, now resolved.
I’ll try to post some pictures of it, and some of another little part for the Märklin 4209 that I also need the P/N and cannot find.
This part is the car number plate # 3798 that goes in between the roof and the side of the car. Again if someone can help with this P/N, I will be very grateful.



Thank you all
Cheers
Carlos

Dear Paul,
In dead I’m really thankful for your help and time consuming with the search of the parts I need.
I am totally agree with you when you Sayed that on the sixties life was more simple. Yes, everything made out of tin and all analogue, things worked and it was fun to see the trains going somewhere in the layout, now with all the technology it seems to be more difficult rather than easier.
As an Aircraft mechanical Engineer, I understand technology, and I like to fix things, and that is one of the reasons I am always looking for parts, I don’t like the simple solution of buying another apparatus to fix the problem, and when I can put my hands on a let’s say Locomotive or car for parts I always do it. The thing is that in this case I couldn’t find any car for parts or at a reasonable price, and there is also the sentimental factor; these cars were offered to me by my Mother who just passed away a couple of months after that, and as you can imagine they have a tremendous sentimental value for me. I also sought in the possibility of purchasing a new set 42041, but then, again is the sentimental feeling, maybe I am too sentimental I don’t know, the other reason I did not buy a 42041 set is that my provider told me that it is possible that Märklin will come out again with these cars in a new set maybe next year or in two more years due to the tooling they used for the 42041 was too expensive just to drop it like that, so I will wait on that to extend my train with another car set. If this won’t happen, oh well…
As for the other part, the little plate, I think I’ll have to wait on Märklin’s answer if it comes someday, at least this part does not affect the cars operation at all it is just a cosmetic detail.
Anyways, I think that Märklin should have, by now, an exploded view and a parts list for all the cars in their program as they do with the locomotives, it looks like @ Märklin nobody cares about cars and/or car maintenance,
At the end of the row it will be easier for everyone.
They have the technology!!!
Once again thank you for the help and if you have any news from Märklin, please let me know.
Thank you
Take care
Carlos
P.D. Please accept my apologies if my English is not that good. My birth country is Portugal, Birth and raised in Lisbon, Left to Ecuador in 1979 and to the States in 2001. Aviation is like that. That’s why my hobby are the trains. Ha!!!

There you go,
That's the reason I never learned Dutch or German. Wow! To hard man! I just stay with Portuguese, English, Spanish, and very little French, I did forgot all my French, too many years living in Ecuador where nobody speaks French.
Lovely that F-16 is it from the Navy, Air Force or just Acrobatics?
About progress I have 3 Sons the oldest is 35 years old and the youngest is 30 years old, you don’t imagine how they treat me, just because of the new technology specially the communicating tech.
I-phones, I-pads, I-tv, I-…, I-…
Even when I have a problem with these apparatus, I call my grandson who has only 9 years old, he can resolve many of those things I can't.
Nothing against progress!
Cheers
Carlos