Sure, the ROM might be, but how are you going to get it on your device? Your device is locked, and there is no sys version in these files, so you will not be able to use them. Also, if you attempt to flash boot or recovery, you will void your warranty and trigger 0x1. Be warned.
you mentioned block size is 512, what should it be 1024? Can we ask @RomDump for a different size, etc.., would that be helpful?
I would think having the 4.2.2 bootloader file is a big plus for research purposes.