To answer some of the other questions and more information in no particular order at all....
Tony's Parts sells both chrome adjuster knobs for these.
The reproduction under floor bracket kit from Harms fits perfectly, great parts.
Power seat adjusters were not available in E-bodies - manual only.
Installing an E-Body 6-way adjuster in an E-Body is easy, I added one to my 1971 Challenger when I had a broken back. It made it much more comfortable to drive. The Challenger was easier to get in an out of than my Ram 3500.
The "6-way" name is a bit misleading, the up and down positions at the front and rear have several settings each, so you can slam it to the floor, or raise both up close to three inches I bet? I have not counted, but I bet there are close to 16 seperate settings possible just with the front / rear up and down settings and many more if you include the front to back adjustments.
I will be installing one in my T/A soon and I will take lots of photos. I will write it up as a technical article and add it to one of my websites. If time allows I will have the article ready by the end of the month?
Oh yeah, I LOVE my 6-way seat adjuster.
T/Ake care,
Barry