I've hiked the entire "gorge" multiple times and you will be very disappointed if you're looking for drops... the biggest one you will find is a 3 ft drop over an old log lol. I would estimate that in the section from Duckfoot to the Curtis ranch you would have to portage at least 2-3 dozen times to get around wood, fences, etc. And no, the road in Duckfoot does not go all the way to the creek, it stops short about a half mile above it.
In addition, there would be no way to cleanly run the private section through Martin's cabin. You would have to portage obstacles and therefor trespass. I'm surprised Ralph let you on their property- if it would have been Jay who actually runs the upper section you would have likely received a resounding hell no hippie
Again, I think the effort it would take versus the reward you would receive would leave you with an overall feeling of "that was lame sauce and totally not worth it." It would not be some glorious first descent.