I'd assume I need to use a hex editor to take the front off the one bios, and add it to the other? Am I at least on the right track?

Lolz, it will not work for many bios implementations as these generally have resource data in modules with specific configuration data headers, compressed in proprietary formats, and with logo data also in some bios propietary image format. So to change that data you need tools provided by the BIOS vendor. In this aspect, AWARD bioses are more mod friendlier because tools for many versions of the BIOS code have been leaked by chinese manufacturers and are widely available. Then you have AMI bioses, which are a win or a miss depending of the BIOS code version and the amount of personalized code implemented by the board manufacturer. Then you have Phoenix BIOSes and the rest of BIOS vendors (SystemSoft/Insyde, Microid, Toshiba, Compaq, etc) which generally are a miss with respect to modding capabilities. These BIOSes have their tools, source code and technical documentation very well controlled and them don't leak often if all, so there aren't many mod tools for them.