The initial packages and source files have been uploaded to
https://mirror.riscyslack.orgI started this from a snapshot of Slackware64-current, its been a little over a month, so its probably a little out of sync with the official version.
I also got tired of fighting with KDE 4 and just dumped it for Alien Bob's KTown 5.19, so a lot of out of sync.
There isn't an installer at the moment, but the packages can be extracted to a folder or drive, and with a couple tweaks, be made into a mostly functional Slackware install.
I put the tarballs with the files from Debian's grub powerpc packages under Other for now.
I just extracted them to root with tar xvf *.txz -C /
They also need libdevmapper.so linked to libdevmapper.so.1.02.1 for the Debian grub-mkconfig to work.
I had to create an /etc/fstab with the mount entries and then run grub-mkconfig -o /boot/grub/grub.cfg to be able to boot directly into.
In case anyone hasn't noticed, I call it Riscy Slack. One because its for PowerPC64LE which is a RISC architecture, and two because its an unofficial build, so use at your own risk.
I'm still working on reverse engineering the process Patrick uses to do all the package signing and stuff for making it look like a proper mirror usable with Slackpkg.