I used a square to mark where I hoped the bolt had gone, and drilled down on that line with a bigger bit. For the one that got off course, I had to do this a second time to enlarge that hole.
After the holes are drilled, and the correction made, it goes together.
The bolt heads stick out a bit. The rails have to fit snug in the corners, so the bolts need to be countersunk.
Initial holes are cut with a forstner bit.
The bit wasn't quite big enough, so it was finished with a chisel.
