Well I have today purchased two Graham Farish goods wagons, they are metal and need tidying up, but they are so heavy compared with modern goods wagons.
They are not boxed, but both runners, they cost me £4 each.
I see what you mean about the couplings though.
I am still stuck trying to get a Bogie for the TRI-ANG "TPO" I bought, I have put it on a temporary bogie for now, but will not run it too much like that, if at all. I hope I can find one somewhre to fit.
I also have a HORNBY DUBLO goods brakevan, the detail made me smile, the window and doors are painted on, but I had to have it if only to sit in the sidings.I enjoy picking up "old timers" like that. Another one I have got is a 4 wheel tank, "esso Royal Daylight Pareffin". It is showing signs of once being well used but it is not too bad really but the couplings are rusty.
I think finding "old uns" like those really make the hobby interesting, even if they make up a train in the goods yard, I think it gives the layout atmosphere of model railways years ago.