Micro-Frets Calibre I, circa the turn of the 1970s, is currently listed with a Buy It Now price of £750, which isn't bad at all for an American guitar of this vintage in good condition. The seller points out that a set-up to your own requirements may be needed, but hey, any new guitar out of the box needs a good set-up these days, so that's no biggie.
And if you don't know why Micro-Frets were so innovative, I suggest you read a couple of blog posts from the archives, here and (perhaps even more pertinently) here.
G L Wilson
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