I restored a 58 Pacer last year. It was the low cost Airstream in 58. It had a leaf spring axle that was in great shape. Even the original brakes that worked very well. So check this one out, it may still be OK. The leaf springs don't necessarily wear or age like the early Henschen axles (started in 62) do. Frame wise I had to redo the tongue and add a cross frame member to replace the one that was right under the rear trunk door. This was done with the plywood floor removed. I replaced all the floor and fixed the frame w/o doing a shell off. Pixs at :
1958 Airstream Pacer
BTW we gave this trailer away last October.