Puppylinux full install to internal (ATA) hard disk

So as I mentioned already, I'm playing with Puppylinux on a small hard drive in kid2, my oldest (still working) desktop computer.

I'm mentioning here some difficulties I had during the install and especially to make it boot properly.  Please note that I'm a complete newbie at Puppylinux, grub4dos, and even to the grub2 configuration/customization that was required to finalize the boot process and keep both Ubuntu and Puppylinux happy, and not destroying the Windows partitions that I still have in this box too.

1. Before starting the install, you'll need the installation media.  I chose to install from a USB card reader (I have plenty of SD cards laying around but no USB stick).  The installation media for the version that I chose (7.5) came in the form of a *.iso file.  However, it turns out that these are not CD images (ISO9660) but rather they appear to be image copies of the SD card/USB stick.  The Linux file command told me that these were MBR formatted disks so I just used dd to copy the file to an SD card.
2. During the install attempt, nothing went wrong really, and I was left with a bootable "frugal" install on my 6GB Maxtor PATA disk.  So far so good.
3. I then tried to configure the Ubuntu disk loader (GRUB2) to boot Puppylinux from this disk.  This proved to be difficult, if only because of the Puppylinux SFS mechanics (layered filesystems mounted using loop(s)).  After some frustration I decided to re-do the install and make it a "full" install (in which the system is booted from a /boot directory directly, and all files are present in the root filesystem like on other distributions that I know).
4. During a first attempt at a full install, something went wrong... I didn't immediately understand that I need to have the USB installation media (still in the drive) manually (re-)mounted so that the installer could uncompress and copy everything on the "bare" root filesystem.  During my second attempt, I mounted my SD card under /mnt/cdrom so that I could select "CDROM" in the installer as the source for this.
5. After that attempt, I was still stumbling on the grub4dos configuration.  Then I understood that the initrd.gz file does contain the code to do the filesystem layering required by a "frugal" installation, and apparently required the SFS files to be present (which I didn't want, as my point was to get rid of these now that I have a "full" install).
6. So I removed the initrd command from grub4dos menu.lst : that worked.  It gave me a hint at reconfiguring also grub2 on the Ubuntu disk, so that I could use both boot loaders as backups of each other.  That part I still have to complete.  In the meantime, below is my Grub4Dos menu entry to boot Puppylinux from the Maxtor:

title Xenialpup64 7.5 (sde1/boot)
uuid abf7b3c6-246c-4189-82a2-a8d41784ba8d
kernel /boot/vmlinuz root=/dev/sde1 ro

(please note that there is no "initrd" command in the above menu entry definition)