Got this bike recently, and obviously things have been modified on it - assuming crank and brakes are original, maybe rear derailleur?

Ukai front wheel, Mavic rear wheel - both QR which I know wasn't common (or done at all then?)
Dia-compe brakes but paired up with Tektro brakes on a riser bar, and only a rear thumb shifter
Shimano Lark SS rear derailleur but Suntour cable guide (??)
Front derailleur and all logos removed except front badge.

Wondering if anyone recognizes the features, colour of it to identify the model (Monterey, Magnum, Avanti, or other?)
This is purely curiosity, so if I don't figure it out then no big deal, I just like to know

Based on the serial # (Y2KC###) it's Yamaguchi, 1982.

Photos as purchased: