All in all, I had a field of about 6 programs that claim to be able to accomplish this feat. A couple of them have more recently been falling out of consideration. One turns out not to support XP. I went to re-image the ailing computer -- while this is still possible -- using Shadow Protect, which had become my secondary imaging program of choice, and which also claims to be able to do complete transfers of installed Windows OS onto a different computer. For whatever reason, the SP boot disk just would not boot up on the subject computer. My 2012 Acronis Media Pack boot disk, which has been my #1 "Go To" choice for a long time, boots up just fine on it. So, there is nothing wrong with the computer's optical drive. (At some point -- the 2018 or 2019 edition ? -- Acronis seems to have dropped support for "legacy" hardware, at least on its bootable media, and became UEFI-support only, a non-starter for these circumstances.)
In the last few days, I took a shot at this with Macrium Reflect, which has also been mentioned favorably by some of you. The imaging with that went well. Next I will see what their expectations and requirements happen to be, for their version of "Universal Restore." My early impression was that -- just maybe . . . ?! -- they have found ways to streamline and simplify this procedure, relative to the others and even approaching the "For Dummies" level. If so, that would be great. Whatever manages to get this project across the finish line will have my gratitude.