wrote

Sounds fishy. If there were a structural problem that required slower
speeds, I would think the FAA would ground the fleet. And, who would
fly them anyway with such a limitation?

Not fishy at all. See my previous post about the windshield heat system.

In addition, I flew the L-188 Lockheed Electra for a couple of years
with an FAA mandated speed restriction due to the wings falling off.

Bob Moore
CFII ATP
PanAm (retired)