Section 57. The town accountant shall keep a complete set of books wherein shall be entered the amount of each specific appropriation, the amounts and purposes of expenditures made therefrom, the receipts from each source of income, the amount of each assessment levied, and the abatements made; and he shall keep his accounts, so far as practicable, in conformity with the classifications and forms prescribed by the director of accounts in accordance with section forty-three of chapter forty-four and in conformity with any systems, classifications, forms and designations prescribed pursuant to regulations of the board of education for use by school committees. The town accountant shall have custody of all contracts of the town, shall keep a register of the sureties on all bonds of indemnity given to the town, shall keep a detailed record of the town debt, showing the purpose for which it was incurred, when incurred, when due, the rate of interest and the provisions made for the payment of the debt.