First thing this morning, I started on making an inside latch mechanism. After a few hours I now have a inside screen door latch that works. I found a chrome handle, I had in a "parts" box, but not sure what it was from or used for and it fit without hitting the door jam. I searched for a couple of hours on the net and still haven't found a screen door latch made by Atwood that looks like the one that came with my Micro-Lite. Will know more tomorrow (maybe) when I call my dealer (who is also an Atwood dealer.)
The original, broken, latch from inside my RV.
The new latch handle and "trip shaft" I put together this morning.