I also have a bunch of rare Ishikawa manga in STK format. They're all in Chinese, though and of low quality. STK is a format read by eReader, which is Chinese program. Really annoying to use, but worth it for such rare books.
I have:
創世戰記
爆末傳
禍MAGA
魔空八犬傳
A lot of these works were paid homage to in New Getter Robo.
Anyone want em?