I changed my kernel using the instructions in "Kernel Compile Guide for 2.6.0" and everything went ok.

I have since changed my mind and wanted to reverse those changes. However I think I've made a mistake and what I would like to do is simply restore everything regarding the kernel source back to its original state before any changes whatsoever had been made, i.e. as it was just after installation of the system.

So I ran "install-packages" from the "slackware/k" directory which I downloaded from a mirror.

Has that restored everything back to normal?

I realise I will have to recompile the kernel, but I was worried about the source, include headers and anything else that may have been changed by my fumbling.

No need to do all that. Simply reconfiguring and recompiling the kernel will take care of the headers and such.

In the future, to keep from doing that, do not build kernels in /usr/src.

This Kernel Rebuild Guide will show you a more excellent way.

Thanks for that link to the Kernel Rebuild Guide Bruce, I will do it that way in the future.

I have installed 12.1 again on another partition - can I copy over that new "virgin" /boot directory to replace the /boot directory on my live partition?

I understand that I will have to run lilo afterwards.

Copied over /boot and ran lilo. No problems

I'm back to normal now and will do kernel configuration changes in a more orderly manner from now on.

A lot of the time I use rsync as root to copy stuff. It will
check the source and destination, and output any errors
to stdout; so your copied data is identical -- i.e.: