Bad spring seats (the rubber ones) do cause a change in suspension geometry and thus, uneven tyre wear.The spring seats rarely fail. Another cause for uneven wear can be worn out inner tie rods. Lift the front end and check if there is side to side play on the front wheels. If there is, the play may be due to tie rods (which have been replaced, as you said) or by the inner tie rods in the steering box (easy to replace, not very expensive. Whatever you do to suspension, stick to OEM components.