The framing for your ladder looks fine but I would worry about the rest of the ceiling framing, it looks like 2by4 on pretty wide centers. I would beef it all up before putting much weigh (or your own body) on it.
Also, is that "knob & tube" wiring still live? If it is you are overdue for some re-wiring.
indeed. i am going to add more lumber, and then 1/2 osb for a landing.
like i said, no way would i put anything on that original framing.
yes & yes, well, it was . but i think the wires going up to the front, are were the original service entered the building. though i could be wrong.
and, while the K&T does look to be in good condition. 1 of the reasons for the ladder is to aid in rewiring.
for the finished look you could add some facade lumber onto the plywood of the door that matches the existing ceiling boards. then trim out around the door with a thicker trim - 5/4 maybe, and this will help hide the fact that the added facade sticks down further than original ceiling boards.
if you consider doing this, be sure to line up the newly installed boards' grooves with the original ceiling boards' grooves so that line of sight is not off