As supplied, the screw couplings in this kit have a whitemetal centre section containing the screw bit and etched strips with eyes for the loops. The eyes slip over projections on the middle. All this hangs on an etched hook.
I didn't fancy this much. The loops would undoubtedly unbend and fall off. I could replace them with lovely versions from CPL or another supplier but I can't be bothered or wish to splash the cash. My plan was much better. If I inserted a brass rod through the whitemetal section, the loops could be soldered to this.
Drilling for the rod was easy enough. Soldering less so. The whitemetal bit was covered in CD marker, oiled and then wrapped in tinfoil to stop solder creep. The ends of the loops were tinned so the bare minimum of soldering would be needed to attach them to the rod.
Deft work with a hot iron and plenty of flux and you know what? It worked. The coupling swing properly and should be usable for running trains. I'm a bit chuffed. The job took over an hour for a pair of couplings, I'd get quicker if I did it again, but the results are very pleasing.
Pedants will point out that it would be better if the handle bit of the coupling swung to the side, or that if it can't (it can't) then pointing forward might be better. I disagree - this way will be far easier to catch with the coupling pole, if not quite as prototypical.