Those Clouser couplers have been around for a long time. I believe that they may fit some kinds of (older?) brass models but I don't have any so I cannot say for sure. So you are very likely in "roll your own" territory. There also are some 1:48 scale coupler boxes on Shapeways. I have used this one with the Clouser coupler on my Atlas O 60' Hi-Cube Berwick car:
https://www.shapeways.com/product/RAV7MNTEX/cr-223331-berwick-pcw-1-8pack?optionId=55158093These boxes are designed for the Berwick and I was able to adapt the Clouser by tapping for a 00-80 screw to install from the bottom. There are a few other kinds of boxes available as well, try searching Shapeways for "Protocraft", "etraxx", "MicroMimesis", and "Jim's O Scale Detail Store". (These things tend to come and go, so if you find one that works it might not be a bad idea to get a few extras.)
Protocraft used to offer another kind of Clouser that had the Kadee style shank but it looks like those are no longer available. They evidently have been replaced with the Symington-Gould version which also comes with its own plastic box. I have not used any of these SGs so I cannot comment on how well they work. The box could probably made to look more contemporary by adding a few styrene strips of the right size.
The SGs come in two varieties: magnetic, which uses a magnetic wand to lift the coupler pin and open the knuckle; and a bottom-operating lift-pin that requires a working uncoupling lever be installed on the car (just like the prototype). For my own cars I am planning to construct working cut levers. I have tried the magnetic wand but did not like it because it tends to pull the couplers a bit out of alignment, so that the next time they have to be re-aligned before the hook can be made.
The Clousers may also need a fair degree of filing to get them to operate smoothly. It looks like the SGs come pre-assembled and pre-painted, which saves work. I do not know if the Clousers and SGs will interoperate seamlessly, but it looks like they might.
Cheers,
Ed
