I was an adjunct instructor at a community college for 12 yrs. I was mandated to pay 7.5% of my salary to the Mass. Smart Plan (deferred compensation) in lieu of SS (OBRA). Six years after retiring,I withdrew the money in a lump sum .I paid federal & state taxes. The SSA now declares that this plan is "for purposes of GPO" a public pension. The state paid no money into this account & I paid all admin. fees. They placed a GPO on my spousal SS benefits & required a repayment of $5,928. I have maintained that the Smart Plan does not conform to any definition of a pension & that the GPO has been misapplied. A friend (PHD in math) analyzed SS's estimate of monthly payments ($134.74) from my Smart Plan. He concluded that the fund would be depleted in 8 yrs. My case is now in Federal District Court. Do you have any advice?
Sorry, but no. It sounds like you are fully familiar with the issues involved with the Government Pension Offset (GPO) provision (https://secure.ssa.gov/apps10/poms.nsf/lnx/0202608100), and that you are pursuing your rights of appeal. I hope things get resolved in your favor.