Today, I made the latch for the passenger door based on advice from Fred Darnell. I used a 1 inch piece of soft aluminum angle on the inside, and bolted the outer handle hole to it with a nylon bushing. I used a piece of case hardened steel (Bowden Cable) to connect the latch to the delrin sliding block. I will go forward with the 1/16 inch cable but had to order some nicopress sleeves. I also made the reinforcing plates for the door bulkhead where the delrin slides in.
