1963 Tel Aviv top of the pile taxed-returned mail for 78 letters using 26 franks

1963 'top of the pile' taxed franking: 10-3-1963 printed matter cover from TEL AVIV branch of Idud Ltd. and franked by machine prepayment at the DO-11 period 8 Ag printed-matter rate, but returned to sender as address unknown (cachet on back); as envelope is printed at base "return payment guaranteed", this letter and all others to same addressee returned together with total tax calculated and applied to one of the covers placed at the top of the pile - here this cover charged 624 Agorot, the 8 Ag return fee (same as sending fee), for 78 letters and paid using 26 stamps on 2 covers, 24x 0.25L & pair 0.12L 1961 Zodiac Ba210/213 (pair 0.25L on 1st cover lighter hue) tied by multiple 22-3-63 TEL AVIV-6 postmarks. Estimated value $430+