Detail of the holes from the outer-dome attach bolts around the periphery of
the LOX dome, where the LOX dome would be
bolted to the thrust
chamber. There are 64 such holes.
Each hole appears to be numbered, although I'm not certain as to the
significance. The three bolt holes fully visible in this photo are numbered
(from left to right) "60", "30", and "56"; the partial bolt hole at right
starts with the digit "2". I suppose that it's possible that the bolts should
be tightened in a particular order, not unlike the star pattern when
tightening lug nuts on a car.