Try this link for the framework for my solution.
So I had both blow out on me on at the same time. I struggled with the plate to manufacture inside. I know I needed 1 1/2 screw/bolts, with spring washers and nuts, not acorn, so I could tighten as much or little as I wanted. Also did not want to reinvent the wheel on the plate, wood, metal electrical plate, etc.
My solution was to actually buy the same base that is on the outside, the one the struts attach to, and use those as the plates inside. Granted, there is a small ball appendage but the plates would line up perfectly and did. Removed the struts, used the outside plate to drill in the existing five holes for both right through the trailer wall. Put the outside plate back on, threaded the 5 bolts in, had my wife stay outside to hold the bolts in place, while I went in the camper, married the bolts with the exact piece bought from the manufacturer, and tightened the nut over the spring washers.
The Plate with ball is hidden by the mattress on one side, and a seat cushion by the other. (A122SESP)
Worked surprisingly well, and have had no issues since.
There is another thread, keyword ACTUATOR (5 pages worth) that details the manufacturer and the many types of plates and struts you can purchase, etc.
Simple, easy purchase, maybe about $4-5 each + shipping. Problem solved.
In fact, I think they are more secure now than the factory.