(IRS claimed that petitioner had unreported business income and sought petitioner's books and records pertaining to business records; petitioner couldn't provide sufficient documentation and IRS sought deposit records to prepare bank deposits to reconstruct petitioner's income; IRS then reduced total deposits by reported income; court determined that IRS introduced enough evidence to establish extent of petitioner's unreported income to satisfy burden of production; petitioner claimed that unreported amounts were nontaxable advances, but petitioner failed to document that claim).