The November edition of Bimmer Magazine has a 5 Series market update that mentions the D'Sylva EAT Chip on an E34 M5. Page 78

"it has a D'Sylva Chip which we never heard of"

It also mentions a 1991 M5, with 92k miles on it, with a rebuilt trans by Jim Blanton. White/Silver Gray

We know this car, I forget the gentleman's name but he was at our picnic last year.

I'll post a pic of the article shortly.