Good luck trying to find a dealer who will transfer it in state for you. Technically a NH gun is illegal in MA unless you bring it into the state having owned the gun already and you are now moving into MA.
The gun is not "illegal" period. Only the act of transferring it is, and only on the dealer- and at that, it's some kind of heavy civil infraction, not a felony like it is with non-roster guns. If an MA dealer transfers the free state version, they'd only be violating the AGs regs, which is a heavy civil infraction for the dealer. (Remember, the PPS is on the roster, so it's always compliant at the bottom tier, just not with the AGs regs except for the crappy MA version.).
I still agree with the sentiment though, good luck with that. It is easier to just buy one of the messed up MA ones and pay a gunsmith to have it repaired.
-Mike