“(3)  If a return in relation to the partnership for any year of assessment has not been made, the person required to make the return under subsection (1) or (2) (as the case may be) shall, within 3 months after the end of the accounting period relating to that year of assessment, furnish to the Comptroller an estimate of the income from all sources of the partnership, and the names and identification numbers of all the partners together with the amount of the share of the income to which each partner was entitled for that year.”.