Postal Seal on 1933 Postage Dues Cover

1933 AUGUST 5: MANILA CIRCULATING
The "3" duplex indicate that this is a Manila circulating cover, posted stampless
possibly drop mail matter. The cover would not have been accepted without franking if coursed through a PO window. Subjected to 4c dues (J8), 2c postage and 2c penalty.

Half of yellow postal seal on back flap used to seal the envelope per pencil
"REC'D OPEN AT MANILA." manuscript pencil notation. Tied with AUG 5 1933 date.
Privately received on front AUG 7.