In September 1977, I rode Amtrak's "Empire Builder" from Seattle to Chicago. I had a roomette in a standard 10+6 sleeper, and the train had the then usual full length dome as the lounge car.
Clearly this isn't going to come close to Dave's experience, but the trailing car was a dome sleeper. It was ex GN or NP and had a buffet compartment under the dome, replacing some sleeping compartments in the original design. However, this was Amtrak, so the buffet was shut. However, the vestibule on this car was trailing and with the upper dutch doors open and only a chain across the diaphragm opening, much of the atmosphere of an open platform was present.
Those who can might recall that in 1977, Amtrak was returning their SDP40Fs to EMD for rebuild into F40PH units which were more suitable for passenger service. Anyway, my "Empire Builder" had four SDP40Fs, two being returned to Chicago for rebuild.
They were all operating, and this was quite a fast trip. I timed a number of mile posts standing on the rear vestibule and we were generally making 80 MPH as far as I could tell, I guess this was really 79 MPH since there was no in cab signalling.
The train was steam heated (all that the SDP40F could provide) so as well as the expected road dust, there was mist of condensed water that helped the dust to stick to you.
Still, it was exciting watching Montana disappear away from you at 80 MPH and I was probably there for an hour or so, since it was a fine, warm day.
However, the view from the air conditioned dome beckoned, and since this was a sleeping car, only four or five first class passengers were there and the atmosphere was more appealing than the crowded main lounge car, where people were smoking.
One passenger had a radio tuned to a local country music station, and I could sit there watching the procession of grain elevators and their small towns pass by. Often you could see a grain elevator ahead before the one behind dropped from view.
It was the end of the post war streamliner era and the cars were showing their age. But they were clean and the bright upholstery looked modern, and the food in the diner was good if simple and not too expensive.
I'd ride that train again tomorrow if I could. I should try the current Superliner version...
But I'd expect that heavyweight end platforms would share the problems of dust and condensing steam heat (that Dave wouldn't have had on his Amtrak era private cars). On a fine, warm day, I'd do it but I'd spend more time in the observation room ahead of the actual platform.