Were the CB750 forks on the Guzzi, or were CB750-style pivots welded onto the Guzzi forks? The Guzzi fork triple trees are narrower, which would explain having to offset the brackets outward.
I might also guess that to take the front wheel on and off, you might have to unbolt one or both of the discs to get them by the caliper pivots. Hence the 2 bolts rather than 6 making for a relatively quick release. The bolts may also have been left a little lose to promote a bit of "floating", primitive style.
It should be noted that the spokes may not be fully engaging the nipples, unless they were over-threaded. Internal threads on the nipple do not start at the top, but about 4mm below the top, so they are actually engaging less than is apparent.