Technical Clunking from offside front strut shortly after replacement - new fault or botched install?

[spleenharvester]

Hi all!

I replaced both front struts as both were showing early signs of failure (misting, later found one of the bearings had failed). Replaced the shock absorber, spring, bearing and top mounts on both near and offside. Nearside looks fine and no rattle sounds. Offside makes a clunking sound going over bumps and on sharp turns. I've noticed the mounting cup is no longer contacting the chassis:

There are two nuts on the strut mount - one underneath the chassis holding the strut together, and the second above the chassis holding the strut to the chassis. I am wondering if possibly I have tightened one or both down too much? I couldn't find any information on how tight they should be/what distance from the top of the thread they should be so I tightened them to approximately where they looked to be on online photos (I had to dremel the old mount off due to corrosion so couldn't copy it). If this is the case should I also replace the rubber mounts again as the rubber will have been tightened down excessively hard?