How to check/change option ROM's vendor, device id?

[JurgisSA]

I have an old motherboard with some SATA to IDE controller and Award-Phoenix BIOS v6. I would like to update my BIOS with the newest controller's ROM. My problem: I am able to extract old and insert new controller's ROM into BIOS with CBROM198, but it's not loaded as new ROM isn't set for needed vendor, device id. Is there a tool/tutorial how to check/change vendor, device ids of option ROM without blindly playing with Hex Editor?

I'm sure that it's about vendor, device id cause I was able to find and compare original and oem controller's ROMs of same, but older ROM version. It's clear that original ROM is set for vendor, device id 1095_1332, while oem ROM for 1002_4379. I need to set new ROM to vendor, device id 1002_4379...

Comparing files 4250.bin (original ROM) and ATI4379C.BIN (oem ROM)
0000003E: 95 02 +
0000003F: 10 10 + vendor id: 1095 vs. 1002
00000040: 12 79 +
00000041: 31 43 + device id: 3112 vs. 4379
00001219: 9E B8 - no idea, maybe some flag
0000121A: 95 02 +
0000121B: 10 10 + vendor id: 1095 vs. 1002
0000121C: 12 79 +
0000121D: 31 43 + device id: 3112 vs. 4379
00001239: 9E B8 - same flag 
0000123A: 95 02 +
0000123A: 10 10 + vendor id: 1095 vs. 1002
0000123C: 12 79 +
0000123D: 31 43 + device id: 3112 vs. 4379
00001259: 9E B8 - same flag
0000125A: 95 02 +
0000125B: 10 10 + vendor id: 1095 vs. 1002
0000125C: 12 79 +
0000125D: 31 43 + device id: 3112 vs. 4379
00001279: 9E B8 - same flag
0000127A: 95 02 +
0000127A: 10 10 + vendor id: 1095 vs. 1002
0000127C: 12 79 +
0000127D: 31 43 + device id: 3112 vs. 4379
0000BFFF: 7D 97 - checksum?