Thanks, Bob; although as usual, there's more to the story.
I've been very kindly and gently informed that the vertical stabilizers are on upside down! Yes, incredible as that may seem.
The kit instructions and diagrams show them the way I installed them, but they are in error, and--dummy me--I didn't think to verify with research.
I'm in the process of fixing this faux pas now, and will post photos of the correction.
And thanks, Gary! I do appreciate it!
How embarrassing! "Aries" has been a real drama queen.