Personally,I'd keep hold of it as it's rare and most importantly sounds excellent. AKAI made some outstanding receivers throughout the 70's. They even had a hand in the development of the TOTL Pioneer QX-9900 quad receiver which in-terms of 2 channel sound quality is up there with the Sansui QRX-9001.
Sure,you could get better sounding receivers like the Sansui Eight Deluxe,Sony STR-6120 and Kenwood KR-7070 etc,but they'll cost.
The only way to vastly better it (especially for TT use) would be to acquire an integrated amp,something like a Pioneer SA-9900,SA-9800,Kenwood Model 600,Sansui AUX-1,AU-919 and Technics SU-8080 etc.