Tonight's progress was all regress. Or, checking other work done, only to find that several bolts in the compression struts had been screwed in at an angle. This is NOT GOOD.
So, taking bolts out, determining the cause is that the compression struts weren't lined up accurately enough (if a small bit of metal obscures one side of the hole, it'll drive the bolt skewed.) Adjusting struts. Putting bolts back in, swearing when they want to follow the new skewed path they've carved threads to follow, taking them out, adding a little percussive persuasion as I put them back in, repeat until straight.
Note to men: I realize some of you love screwdriver-type handles on 1/4" sockets. On the other hand, some of us haven't been building our forearm muscles since we first hit puberty, and think they suck dead rat. Through a straw.