Not following you exactly. What you need is for the part that holds the shock to get tight w/o crushing the shock, and the part that anchors to the trailer to get tight and not move despite the shock only being sort of tight.
Take a close look at the pic in
this link.
This is a thru bolt style where the stud anchors through a hole with the nut on the back side. The thick washer is compressed between the mounting surface and a step on the stud so that the space for the shock is fixed between the large washer and the flange of the button head. The button head has wrench flats on it so that you can hold the stud while tightening the nut.
Compare that to
this style (#75-5100).
The stud is double ended and has an integral hex in the center with a thread and nut on one end for securing to the anchor point, and a smaller diameter thread with shoulder and washer on the other end to prevent over crushing the shock bushing when the retainer nut is securely tightened.
Both of these designs have two things in common; the stud mounts securely to the anchor point with no chance of relative motion, and the shock is maintained securely without crushing it or allowing it to become loose.
The links are just sites that had good pictures of what I was trying to explain. I have no affiliation and have not looked for better pricing (although Speedway is usually pretty good).
I don't think it is worth it to try and bodge something together. I think I paid around $5 each at my local parts store.