I'll spare myself from repeating your admonition as I agree with it completely. I suppose my "long-term storage" comment was a bit misleading as the coat actually spent its entire life (perhaps several decades) on a rack prior to my acquiring it unworn, but for practical purposes it could as easily have been in a closet. After speaking with the local dry cleaner I'm not going to take any action for now as the issue isn't significant enough to risk damage to the coat.Repeat after me-
NEVER EVER WASH OR LAUNDER A SPORTCOAT OR SUIT.
I've seen the above garments after being hand & delicately laundered.
It's guaranteed ruin the interlinings & destroy the finish on the fabric.
You may simply need to send the garment to the landfill & avoid storing garments similarly in the future.