Notwithstanding any general or special law to the contrary, the Massachusetts teachers’ retirement board shall credit Thomas Struthers, an employee of Shawsheen Valley Regional Vocational Technical High School, with 3 years of creditable service for the period of 1983-2000, inclusive, when he worked in the occupational field in which he teaches, for the purpose of determining his superannuation retirement allowance under paragraph (a) of subdivision (2) of section 5 of chapter 32. Before the date that any retirement allowance becomes effective in the case of Thomas Struthers, he shall pay into the annuity savings fund of the Massachusetts teachers’ retirement system, in 1 sum or installments, upon such terms and conditions as the Massachusetts teachers’ retirement system may prescribe, an amount equal to that which would have been withheld as regular deductions from his regular compensation for such previous service, together with buyback interest, as defined in section 1 of said chapter 32. This act shall not affect any other retirement benefits that Thomas Struthers may otherwise be entitled to.