Some differences in hard coding between Call and JMP
The four bytes after the 0xFF15 CALL is the address where the address is stored.
The four bytes after the 0xFF25 JMP is the address where the address is stored.
The last four bytes of 0xE8 CALL are addresses.
The last four bytes of 0xE9 JMP are offset.
The four bytes after the 0x68 PUSH are stacked.
One byte after 0x6A PUSH stacks