After searching for a right hand latch with the correct notch, I came up with nothing. However, looking at the comments / reviews on Amazon, this problem is fairly common. A lot of Forest River RV's from the '00's had these latches on their Amerimax doors.
The solution is to take apart the old latch and the new latch, and switch the backing plates. Using the JR Products 10765 latch front with the old back, it fits perfectly. Each latch has 5 clips that you can release with a small flat tip screwdriver. The only part you have to worry about is the interior spring - don't let it get away. Press the parts together, and wa la! The screen door latch closes with authority now.
Here's the grafted parts, front and back.
2007 Coachman Freelander 26' w/ E-450 6.0L diesel
1982 El Dorado Bermuda 27' w/ E-350 460 gas (sold)