I'll try to answer on what I know about it.
754 I just bought it, I went to look at some parts, as soon as I seen it, I knew I had to have it. The guy built it 30 years ago, and it has not run in nearly 30 years. It was not originally for sale, but I wasn't leaving without it.
Yes all power goes through the rear gear box. I think this one was built mainly for fun and not for any serious racing.