I do believe this project is cursed....
I was looking at the loose parts of this kit and decided to take a closer look at this one;
I couldn't find it on the downloaded assembly instruction sheet. So I took a look at the ship to see where it might fit.
It took a few seconds for me to locate where the part might fit....
I placed the part in that location and ascertained that it was upside down. The part was meant to be attached so that its taller section would protrude above the deck. Unfortunately, the openings which it would've fit it in have been blocked off by the thick plastic card I had used to get a level deck.
Looking closer at the instruction sheet, I saw why I hadn't noticed this detail previously. The design of the deck part had been changed from the version depicted in the diagram. The mystery part, circled crudely by hand using the Preview app, wasn't shown in the diagram of the deck assembly step.
I had another issue trying to locate a phantom part when I did the dry fit of the forward bridge tower parts. Once again, I had been misled by changes to the design of the kit which were not reflected on the instruction sheet. The two parts circled in red in this diagram had been re-engineered as a single part.
That combined part was a touch difficult to put in place. I filed down and shaved away its insert base to get it to slide into position. Yet, even though I had glued the part in front of it (the part left of the left circled part in the above diagram) in place, that part was lifted slightly out of position when I got the tower part in.
Though I had said I was going to put the ship's boats on first in my previous post, I decided to proceed with assembling the tower bridge. I wanted to get the tiny parts out of the parts box and safely onboard the ship.