"SECTION 92. Discharge of Executor or Administrator from Personal Liability. - If the executor or administrator makes a written application to the Commissioner for determination of the amount of the estate tax and discharge from personal liability therefor, the Commissioner (as soon as possible, and in any event within one (1) year after the making of such application, or if the application is made before the return is filed, then within one (1) year after the return is filed, but not after the expiration of the period prescribed for the assessment of the tax in Section 203 shall notify the executor or administrator of the amount of the tax. The executor or administrator, upon payment of the amount of which he is notified, shall be discharged from personal liability for any deficiency in the tax thereafter found to be due and shall be entitled to a receipt or writing showing such discharge.

"SECTION 93. Definition of Deficiency. - As used in this Chapter, the term 'deficiency' means:

"(a) The amount by which the tax imposed by this Chapter exceeds the amount shown as the tax by the executor, administrator or any of the heirs upon his return; but the amount so shown on the return shall first be increased by the amounts previously assessed (or collected without assessment) as a deficiency and decreased by the amounts previously abated, refunded or otherwise repaid in respect of such tax; or

"(b) If no amount is shown as the tax by the executor, administrator or any of the heirs upon his return, or if no return is made by the executor, administrator, or any heir, then the amount by which the tax exceeds the amounts previously assessed (or collected without assessment) as a deficiency; but such amounts previously assessed or collected without assessment shall first be decreased by the amounts previously abated, refunded or otherwise repaid in respect of such tax.