Assuming the issue you have relates to the missing left-hand-side options when looking at a sellers-other-items page ... I think this is a well reported problem which is being looked at.
In the meantime it is possible to copy the seller id, and use the Advanced Search by Seller and paste in the seller id. The search results page should have the original controls and allow you to see previously sold items.
It is fiddly but hopefully the original problem will be fixed soon.
