Your edits have affected CP 0x55 and CP 0x56. There is an XOR checksum byte at the end of the CP. This must be recomputed so that the XOR checksum is 0x00. In short, don't touch the ROM. Just leave it alone.
Code:
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000000 4D 4E 20 20 20 20 20 20 20 20 20 20 20 20 20 20 MN
00000010 20 20 20 20 20 58 58 58 58 58 58 58 58 58 54 4F XXXXXXXXXTO
00000020 53 48 49 42 41 20 4D 51 30 34 55 42 44 32 30 30 SHIBA MQ04UBD200
00000030 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00000040 20 20 20 20 20 20 00 00 00 00 00 00 00 00 00 00
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000080 00 00 00 00 FF 3F 10 3F B0 88 E0 E8 00 00 00 00
00000090 05 01 00 01 00 00 00 00 00 00 00 00 00 00 00 00
000000A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
000000B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 DA
Your ROM is divided into a code section and a CP section.
The CP section begins at 0xD7000. It appears to be OK (apart from your edits). See the attached CP dump and CPlist.txt.
There is a 6-byte CRC of some kind at the end of the code section (offset 0xD6F78). I don't know how to calculate this CRC, so the only solution I know would involve comparing the code section against a ROM with the same version. That said, the very first byte seems in error. It seems that it should be a "C".
Code:
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000000 00 6F 70 79 72 69 67 68 74 20 31 39 39 39 20 54 .opyright 1999 T
^^
00000010 4F 53 48 49 42 41 20 43 6F 72 70 6F 72 61 74 69 OSHIBA Corporati
00000020 6F 6E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 on..............
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000080 00 00 00 00 00 00 00 00 78 6F 0D 00 00 70 0D 00
00000090 00 00 00 00 00 00 00 00 00 00 10 00 00 00 00 00
000000A0 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00
000000B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 18 9C