if the net proceeds of a sale or the net indemnity for a loss is deposited in more than one deposit, the amount consisting of the gain shall be deemed to be deposited first;

amounts expended, obligated, or otherwise withdrawn shall be applied against the amounts deposited in the fund in the order of deposit; and

if a deposit consists in part of a gain not recognized under section 53306 of this title, any expenditure, obligation, or withdrawal applied against that deposit shall be deemed to be a gain in the proportion that the part of the deposit consisting of a gain bears to the total amount of the deposit.