1965 Jerusalem to Tel Aviv underfranked & revenues-franked mail - accepted, not taxed

1965 Jerusalem to Tel Aviv underfranked & revenues-franked mail - accepted, not taxed
1961 revenues-franked domestic mail: 15-5-1965 commercial cover from travel agency in JERUSALEM to hotel in TEL AVIV, franked 10ag instead of the DO-11 postage period rate of 12ag, using an invalid 1961 series revenue stamp - this accepted at the JERUSALEM Post Office which applied machine slogan cancellation to the franking and the underpaid rate; opened at back. Unusual accepted double-fault.