Section 28. All claims shall be made as of the date of the distribution of the fund, interest being allowed or discount being made to that time. A creditor having a claim for which the insolvent is primarily liable, and others secondarily, may prove for his whole claim; but, if the insolvent is only secondarily liable, the value of the liability of the primary debtor shall be adjusted between the creditor and the assignee; or, if the valuation cannot be agreed on, the same shall be submitted to the appropriate tribunal, and a dividend shall only be awarded to the creditor on the difference between such value, so determined, and the amount of his claim. In like manner, any collateral security held by any creditor for his debt shall be valued by said tribunal, and if the security be retained by the creditor his dividend shall be on the difference between his claim and the value of his security, so ascertained: Provided, That the creditor shall have the right to surrender his security, and take a dividend on his whole debt. If such creditor refuses to have his security valued or surrender the same, he shall be excluded from participation in the fund.