One word of caution: I recently put two early 1980's Scheels I have into my E9, using the Scheel seat rail adapter. IIRC, these are the 400 rally model with aggressively sized shoulder bolsters and very firm/supportive urethane foam guts.
The seating position is considerably higher than with a stock seat, and also much higher than the Recaro's that were taken out of the E9. If I were about inch taller, I wouldn't fit anymore and I'm only 6' (this is a sunroof E9).
I'll revisit the Scheel bracket to see if there's some way to lower the seat with a custom made adapter.
I was very excited to install the Scheels as they served me extremely well in my 2002 during grad school 3 decades ago. But now I'm 'bigger' by 50lbs, and I suspect I'd prefer a set of OE sport seats from an E28 or E24. If I had Duane's svelte figure it might be different. If newer Scheel-Mann seats have a lower/thinner seat cushion it might not be an issue. Eventually, this car will be put into Mario's capable hands for a restoration, at which time we'll discuss the idea of creating lower seat mounting points (with an spacer to bring it back to stock height if needed).
John