Circuit Diagram for one DIY preamplifier bid from Japan

The kit was bid from Japan, labelled that it was made by 1986, imaged with Pioneer AU-999. I think it is a pre-amplifier, but cannot get a circuit diagram from the internet websites. As enclosed with the pictures for searching the circuit diagram if having. Thanks a lot.
 

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Thanks to Planet10 & PRR, Sansui SS, will take this way to search for its circuitry. So far, has any idea to have its actual model number. Transistor part for the equalizer and put the 12AX7 + 12AU7 for the pre-amp. The components are worthly valuable. Thanks a lot.
 

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Actually it was handmade, uptill now 46-years, for its talent the people rightnow is 70~80. Tested that 1 x AX7 and 1 x AU7 is faulty, separately with Transistor EQ + Tube Pre-amp, opportunity to tune up possibly only the tube then the EQ. Let take time to try.
 

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