OK, all the makes succeeded. The 1st and 2nd copy commands failed because there’s no .dtp directory in either arch/arm/boot or arch/arm/boot/overlays. The last 2 copy commands succeeded. Any suggestions?
Also, am I correct in assuming that copying things into the /boot directory will make our new kernel the default kernel that my Pi will boot with? If so, how easy will it be to switch back to the existing kernel?
Thanks again for all your help!