I had a response from my craigslist ad. Found a guy with a 5-6 yr old Riptide transom mount with a 36 inch shaft. Used it "briefly" on a canoe and hasn't used it since. Only wanted $100 for it.
If your interested, his email is jwooland05@comcast.net
Found. Riptide 40# $100
Moderators: bman, Chalk, Tom Keels
Re: Found. Riptide 40# $100
Email sent.
"You cannot change the wind, you can only adjust your sails." Del Suggs
Re: Found. Riptide 40# $100
Contacted, viewed, purchased. Just right for the War Eagle 1548. 
Thanks for the info bbb.
Thanks for the info bbb."You cannot change the wind, you can only adjust your sails." Del Suggs