E30 Zone

I just finally got around to stripping the bodged subframes off my bucket seats, they were in a Tigra before .

What I am left with is 4 threaded boltholes. I am thinking there must be e30 specific subframes that bolt on to these? Anyone have a idea?

What is the spacing between the bolts or what make are the seats?

seats are edenz, i'll measure the spacing tomorrow