I'm sorry...it is dead. The dark mass, yellow color, and no visible veins are all indicators that it is gone. You can see a few broken decomposing veins if you look close, but no active ones. Again, I'm sorry. You gave it a good shot. But without a good incubator and an auto turner it's just...
Yes, the parents turn them a lot but I'd do at least five times a day or so. Draw an X very lightly on one side and an o very lightly on the opposite side with a pencil. Then you go back and forth between the sides. So as an example, the egg is on X at nine a.m.
At 12 you turn it left to o and...
#1 is good, the rest are not. If they were in the same nest they'd all be about the same amount of time along, so would all look like #1. The other two look infertile or quit very early. You can leave them in if you want, but they're duds. Pigeons develop very fast, if you look close you can...