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I see a fourth option:
4) Make a new post (the cylindrical part, which might be easier). That is only *one* part to make, instead of a half dozen or so. Make it a little oversized, and bore *all* of the holders (the ones which came out right and the ones which did not) to fit that one. I would suggest boring one of the bad holders first, to see how much is needed to make it clean up.Out of curiosity -- what kind of endmill was used for the failed attempt, and did you have a hole drilled through the center of the workpiece before you hit it with the endmill? Most endmills that I know of that size are not center cutting -- at least ones which will fit *my* machines. Those which I have only have the end teeth going about half-way to the center, and then there is a recessed area with a female center for additional support while sharpening the endmill. Thus, for these, a hole about half the size of the endmill OD would be needed before you tried the endmill itself.
Good Luck, DoN.