Pretty rare, almost non-existent.
Given the poor sales of the TX-1000, Nakamichi needed a cheaper solution to carry its warmly received solution to the radical illness of the LP format : enter the CT.
If the TX-1000 was designed by Etsuro Nakamichi (but quite probably built by Micro Seiki), the Dragon CT was "sourced" elsewhere : Nakamichi commissioned Junichi Okumura, then at Fujiya Audio Ltd, to design the CT after the basic goal outlined by Etsuro !
This explains the large differences in approach and engineering between the TX and the CT.
Fujiya was later in the 1980s absorbed by NEC and units such as the Dragon CT were scrapped from the books. And when NEC shut down its own audio/video activities in the mid 1990s, well, the Dragon CT definitively vanished from the landscape.
Thanks to Shinichiro Okumura, son of Junichi, for unveiling this revealing bit of history.
According to one service engineer, the Dragon CT was much more reliable and better sounding than the bigger TX-1000. I wouldn't know but the goal was basically the same - and the same as that used in the original Dragon cassette recorder, only on a larger scale.
Off-center records are a pain and there isn't much one can do if the record is pressed that way !
Well, there is something one can do : search for the real center of the record and adjust the turntable platter to budge so that the off-centered record can be read as if it were not off-centered. No small feat on a cassette recorder (for proper head azimuth) but imagine that on a record player !
So, the little arm at the back scans the record groove, decides where the "absolute center" is and the whole turntable assembly then moves accordingly - the cart is no more pushed around left and right and just reads the groove.
The main tonearm with interchangeable wands was sourced from Jelco.
This is a temporary page :
I have finally, yes, found, yes, the original japanese catalog for the Dragon CT and, yes, for the TX-1000 - yes again !
This page will therefore be updated in full very soon.
In the meantime, you can see one at hifi-do (see the penultimate image and the Fujiya logo next to the T-Tag :) and another showing the platter assembly.