...went to other side to change brake shoes: with hub bolts off, I reinstalled the wheel and bumped the tire...with some conviction. The drum pulled away in seconds.
Now this syndrome of show linings separating is something that was rare years ago. OF course, those using rivets would not separate, but bonded type would certainly stay until worn out. I found the one that separated might have been contaminated by a very small amount of brake fluid as some trace existed on the brake cylinder (no trace on the other side..and linings were tightly bonded): hey I had seen fluid and oil contamination in severla occasions long time ago and linings would stay on and after some thourough cleaning, went back in service...but I suspect DOT3 type fluid..I mean these brake fluids that are not the old original type..so yeah, "advanced" brake fluid might be a better solvent for lining bonding, and that would explain this kind of trouble being very common to-day...as I can see around me .