Oh, sad news. May be that's the reason no emails were replied. Anyway, the knife may have the brand Tanaka, not that he forged it. May be his son or his crew.
In the Metalmaster website it mentions it has:
Who is Hideyuki?
Also in the website it mentions 170 gr. but that's inaccurate. Here are the measures:
TANAKA GINSANKO 210 mm. GYUTO
Weight: 150 gr.
Length of the blade: 210 mm.
Total length: 350 mm.
Width at the heel: 49 mm.
Thickness of the spine at the handle: 3 mm.
Middle of the spine: 2.5 mm.
Heavily tapered from spine to edge.
Edge profile: a sector of ellipse, which I find is the perfect gyuto curve.