I am missing so many parts that this is all I can do now.
I did make some mistakes. I had to drill out some rivets that I put prematurely on the side that attaches to the seat bottom.
I found that the length of the rivets on the plastic spacers that hold the seat release handle were not long enough. It calls for 3.2 x 8m. But I used 3.2×12.
This was a cool part to make. Gotta love gadgets. Felt a little steampunk.