I am attaching two files ori. One 832kB and one from 896kB.
If the mo cut as you say, I get a file of size 864kB. Can not go.
The file with 896kB have a size of 917'504 bytes
The file with 832kb have a size of 851'968 bytes.
The difference of 65536 in decimal, Hex are 10000, just what you need to cut between 0x8000 and 0x18000.