Steve,
I would not part with this cue for any reason. It represents John's work extremely well, perfect inlays, points and colours.
If I were in your shoes I think I would have to put the beauty part apart when choosing the cue(s) to sell as based on this factor every cue in your collection is a keeper - they are all perfectly executed.
I think you should create a rating system, some sort of a test for yourself and hence rationalize your sales... I, personally, would rate the cues in terms of sentimental value (#1); chances of future replacement, i.e. repurchasing it or finding another matching the current cue's specifications rather well (#2) ; sales value / chances on a quick and most profitable sale (#3) and maybe some more. I think I would add 0-20 points or maybe 0-10 and I wouldn't redo the test. Your first intuitions, feelings are the true ones most likely and I'd try to stick to those.
You have fairly enough cues to have the need of a system, it would make it easier not to miss anything out and to make the proper decisions.
Just a kind recommendation / idea from a guy who learned too many of this stuff lately and gave it a little twist...