Notwithstanding any general or special law to the contrary, the state board of retirement shall credit Jason Patrissi, an employee of the probation service and a member of the state employees’ retirement system, with up to 6 years of creditable service for the purpose of calculating his superannuation retirement allowance under paragraph (a) of subdivision (2) of section 5 of chapter 32 of the General Laws, for service rendered for the state of Vermont’s department of corrections from December 1998 to March 2006; provided, that such service rendered in Vermont was equivalent to the service rendered by Jason Patrissi in the Massachusetts probation service, as determined by the state board of retirement; and provided further, that Jason Patrissi shall pay into the annuity savings fund of the state employees’ retirement system, in 1 sum or installments and upon such terms and conditions as the state board of retirement may prescribe, an amount equal to the contributions that would have been withheld as regular deductions from his regular compensation for such period of service, together with regular interest thereon, as determined by the board.