My current thoughts are that the Freedom 28 was the earlier one at Oshkosh in '86 and that a version called the
Freedom 40 appeared in the nineties! Your photo looks like a single and I suspect it's a 40 and wrongly labelled.
The photo of a 28/40 in my first link above, does show the exhaust, so maybe that's not a 28 either, and the forty was another model
Edit: It seems the designer Neal Brutsche died in 2003 and on a homebuilt forum someone was replying to his brothers announcement and obit said he was looking for plans eight years earlier for the Freedom 40