Folks, the Post Office management signed those contracts with the unions. The unions did not hold a gun to their heads, management agreed. With respect to pensions. A reasonably simple calculation based on the number of years that a person works (about 45) and the number of hours in a work year (2080) one can easily figure out what a reasonable pension can be. The problem is that reason has flown out the door. We need reasonable values and a person has to save for retirement.
100% of everything they do or have available is publicly available. Just look up FEDERAL RETIREMENT OPM (that's for office of Personnel Management ~ they run the plans).
Regarding management signing the contracts, postal workers are under a NO STRIKE LAW. Instead the law provides for BINDING ARBITRATION.
The Arbitrators have historically ignored every management offer and all economic studies and imposed, through binding arbitration, the union requests on the organization.
Go see your Congresscritter about BINDING ARBITRATION. He'll answer all your questions (if he's sober).