The county shall be relieved of that part of its obligation to the state for ninety per cent (90%) of the state school tax when the county treasurer shall have filed with the state treasurer receipt from the custodian of the school district, which receipt shall acknowledge the acceptance of county and/or municipal scrip or other obligations of the municipality as payment for amounts due such school district from the county treasurer on account of the distribution of the state school tax, if with such receipts there is paid to the state treasurer the proportionate cash payment due the state.
N.J.S. § App.A:4-49