Yo dude you're going to have to do some reversing and binary rewriting. Looks like the APIs have changed in 10.9, which is to be expected. How significantly is the question. I might have some time tonight to bust out IDA Pro, but the linker might also run into further errors after fixing the first few, so this could easily take me a week+ if I didn't have a day job.
This is what happens when you try to load Resman. There might be an easier hack, but I don't know objective c internals well enough to know... so my first approach would be to determine what the assembly looks like when a class uses OSDeclareDefaultStructors and OSDefineMetaClassAndStructors and try to inject that into the OSObject classes the binary so it can link properly.
Jul 1 11:38:09 localhost com.apple.kextd: WARNING - Invalid signature -67050 0xFFFFFFFFFFFEFA16 for kext "/Users/mark/oldnvidia/NVDAResmanWeb.kext"
Jul 1 11:38:09 localhost kernel: kxld[com.apple.NVDAResmanWeb]: Relocation failed because some class in this kext didn't use the OSDeclareDefaultStructors and OSDefineMetaClassAndStructors, so it still references __ZN9IOService19_RESERVEDIOService0Ev, which has been patched with another symbol for binary compatibility. Please make sure all classes that inherit from OSObject use these macros.
Jul 1 11:38:09 localhost kernel: Can't load kext com.apple.NVDAResmanWeb - link failed.
Jul 1 11:38:09 localhost kernel: Failed to load executable for kext com.apple.NVDAResmanWeb.
Jul 1 11:38:09 localhost kernel: Kext com.apple.NVDAResmanWeb failed to load (0xdc008016).
Jul 1 11:38:09 localhost kernel: Failed to load kext com.apple.NVDAResmanWeb (error 0xdc008016).