I’d back up what Peter says here. In use isoelastic bushes are held still in the outer and inner bushes and the rubber twists to take up the movement required. Your inner bushes are not supposed to be a tight fit on the spindle but are supposed to be clamped firmly when you tighten the nut up and trapped against the frame so they can’t move. If you have play in the swing arm there are 2 possible reasons: the bushes have broken up and are perished or slack leaving the inner free to spring about in the bush; the spindle is loose letting the inner bush move around the spindle. If the bushes are perished you’ll have to replace them but you’ll have doubtless examined and sorted that by now.
When re-tightening isoelastic bushes remember to leave the spindle loose and tighten it while getting someone to sit on the bike to ensure the bushes are tightened in their normal running position. This increases life expectancy no end!
I hope this is of some use to you.
All the best: