first of all: welcome to the Yamaha forums!
Where from did you get that information that there is a DX7 II Plus somewhere out there? Never heard or read about such a model...
My gear (in alphabetical order):
Kawai: K1 II
Korg: M1, M1R, Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID, EX5R, RM50, RX5, SY99 (with 'Cool Blue' mod), TG500, TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x)