Sqwak7700,
"When they were hired, they were told that retirement was at 55,"
They were also told that they were on A-scales and having had that contract broken by the company at least twice they are fully entitled to expect to make up their financial losses by working on.
I'm sure they're not bothered whether they have your sympathy or not but facts are facts and you are correct that they've accepted the substandard package (unless they're trainers).