@trumptrain-Thanks for the pictures of that gondola Mate!
Here is an early Marx train for today's T.E.T. This is a group of "Bogota" passenger coaches with the short, silver lithographed frame and Joy Line couplers dating them from 1934-1935.
Here is the front end of the same train, pulled with the ever present "Commodore Vanderbilt" #597 locomotive which was available from 1934 to 1952. However the black wagon top, 8 wheel tender, is from 1934 and 8 wheel, 6 inch cars of any sort never returned after the war. So my guess is that the entire train is circa 1934-1935 (after 1935 the Joy Line couplers were replaced with the far more common tab/slot couplers).
Best Wishes everyone
Don