Would there be any problem if the shocks were at a wrong angle? I can see if they were mounted vertically the would have problems and if they were angled too much. When I put tubulars on my 49 I made a frame/bolt template from my 53 using cardboard and then plexiglass so they wouldn't tear. It helped but am certain the mounts are not in the exact place they were on my 53. Maybe off a few degrees but the ride is fine. I used stock mounts salvaged from a wrecked chassis.
The only issue that I am having is extra stress on one edge of the rubber doughnut from the wrong angle.
Carl