Making and installing the SysVinit binaries is pretty straight forward. I'll just be lazy and give you the commands, assuming that you have unpacked and entered the SysVinit source code directory:
cd src make ROOT=/mnt/target make install
There are also a lot of scripts associated with init.
There are example scripts with the SysVinit package, which work fine.
But you have to install them manually. They are set up in a heirarchy
under debian/etc in the SysVinit source code tree. You can
just copy them straight across into the target etc directory,
with something like cd ../debian/etc; cp -r * /mnt/target/etc.
Obviously you will want to have a look before you copy them across!
Everything is in place now for the target kernel to load up init
when we reboot. The problem this time should be that the scripts won't
run, becasue bash isn't there to interpret them. Also, init
will try to run getty's, but there is no getty for it to run.
Reboot now and make sure there is nothing else wrong.