HI,
Regarding the access to the upper level of these Paris Versailles RG, I do not see any step iron in the carriage ends. It seems - for the 1/2 class carriage - that such step irons were fixed on the faces of the 2nd class compartment, not sure. I will try to check this point.
Also I wonder why these seats on the first class where used for. I am not sure that brake was available at the early days, but may be the first class carriages needed some seats for the servants ??
These opened carriages where very dangerous, not so much while embarking/desembarking, but when approaching bridges and tunnels (especially on sundays when exited passengers coming from the french guinguettes were going back home with the trains de plaisirs. At this ancient time, the conclusion of the accident was probably "he did not take care".
May be the number of accidents of the eastern railway leaving Bastille station was lower. The Est introduced the closed carriage very early (Bidel) while the Ouest who had a huge number of open cars, only introduced a very limited number of closed cars (110 units) around 1895-1898.
I recently found that a bridge, not far from Paris St Lazare station, was nicknamed la Guillotine. It had to be rebuilt in order to give more space between the bridge piers and the carriages.
Looking outside was not a good idea !
roland