Possibly Version 3
After comparing hexdumps of a Defy 2.2.2 Version 4 CG31.smg and Bravo 2.2.2 CG31.smg from sbf, I believe we're Version 3. Other than the signature of the file, the only changes are literally, 4 bits. 4 to 3 in two spots and 1 to 2 in two others. You'd be surprised how similar they are bitwise and that key partitions are identical in size, only change being how its signed. Makes you wonder what the differences are between 9.10 bootloader (Defy) and 9.12 bootloader (Bravo).
I also saw the 4-3 1-2 change in CG35.smg (bootloader) as well. It's also very similar bitwise. I'm not sure this will help anybody, but its interesting.