So, I took the steps of forking Jude Nelson's vdev on git.devuan.org,
and augmenting it with an initial set up for deb package building.

I set it up as three deb's:
    libudev1-compat to replace libudev1,
    vdevd being the daemon, and
    vdev being the configuration, initramfs building and the set up as 
sysvinit startup script.

I've built sample packages for amd64, and tested on a pristine Devuan
1.0.0, (with DE+Xfce, printer server and ssh server). Available at

https://git.devuan.org/ralph.ronnquist/vdev/release

If you download those and install together (as in dpkg -i *.deb), your
system will change into using vdev rather than udev, but it doesn't
uninstall udev for you. It "only" removes udev's sysvinit scripts, and
udev's configuration for initramfs building, and the "init" script
(replaces the one from initramfs-tools).

When installing, it might warn about volume symlinks not being created.
It's is safe to ignore this. Alternatively you install lvm2 first.

You can also build your own deb's by cloning
https://git.devuan.org/ralph.ronnquist/vdev

and using
$ make -f debian.mk

provided you have dh_make and dpkg-buildpackage, as well as
build-essential. Since I'm quite new to package building, it only
contains the bare-bones so far. There are also no upstream changes to
source other than to Makefile's and initramfs scripts, with the
exception of the very minor patch to vdevd/helpers/LINUX/udev-compat.sh.

As a side note, eventually I realised that the main issue why the
keyboard didn't work, was that the evdev module didn't get installed,
and that it needs to be installed before /dev/input is populated.

Ralph.