The British Library has a new OPAC and therefore a new link for searches.
I corrected the search target for the British Library in D-D.
PS: the search/order target for the KOBV has also been defect for some
time, due to changes on the side of the KOBV. Nobody did seem to miss
this order link, so I did remove it...
...unfortunately it's not very common that system librarians do
communicate changes over mailing lists.