Basic of basic questions but I'm stumped ... component out of vertical ... how do I get it back

I have a component that evidently, I inadvertently got slightly out of vertical and I can’t restore to a vertical orientation. What am I not doing wrong? (A lot, no doubt.)Wood box rev 1.skp (30.7 KB)

I realigned the top cross piece with the lower one, then rotated the panels to vertical. To set vertical, I used the Tape Measure tool from a corner of the bottom piece.
Wood box rev 1.skp (25.4 KB)