If anyone is interested in working on testing the current version of 
sysinst/mac68k I've submitted the patches via send-pr.  The PR is 
install/10811 titled "Sysinst/mac68k sometimes corrupts disk during 
installation".  If anyone has problems, questions or comments about the 
PR or the code I'd be happy to try to answer them.

Unfortunately I can't build Installation Kernels at the moment so anyone 
who wants to work with this will have to do their own builds.  I 
understand that might change in the near future though.

Thanks,
-bob