Otto Eisenschiml's background

[Gene C]

Guttridge and Neff's Dark Union is a serious work of solid scholarship based on years of research, and there is no comparison between it and Balsiger and Seller's book or Bates' book.

If you think there is no comparison to Balsiger and Seller's book, "The Lincoln Conspiracy" you are sadly mistaken.
The B & S book was published in 1977 and Ray Neff's in 2003.
Ray Neff makes no reference in his book Dark Union to any "absurd speculation, distortion, or outright fabrication" in the Lincoln Conspiracy book.
Are you aware of any written statements Neff made to distance himself specifically from any statements made in the the B & S book?
He certainly had plenty of opportunity (25+ years) to do so.