Jimjung..No. 1, 3, and 7 need some more looking into...
No.1 (Scott 77xx-Style T) (DIE I) may have been tugged slightly during printing.
No.3 (Scott 75xx-Style T) (DIE I) can be a shifted down of the precancel with the top bar being the bottom bar of the above precancel.
N0.7 (Scott 35xx-R)looks as though the precancel was printed vertically and then the sheet was possibly reprinted horizontally...Should only look like the stamp below

Now I am NO expert on these precancels and would love to hear other opinions..
Robert