I made this ladder. Pretty easy with common tools. I used 3 8' sections of poplar that was finish grade. Measured the length, cut to size and the treads are 12" wide and I think 10-12 rung spacing so it was kid friendly. I also cut small pieces of wood to go under each step and screwed them all together and surprisingly it hold me. 240lbs. Took about an hour or two. Stain was stuff I had on hand. Then I took two small "L" shaped brackets and screwed one side onto the ladder and the other side is to just keep the ladder from sliding outwards. Total coat was around $25 with the urethane.
If it weren't all closed up, if get better pics for ya.