Thanks Adrian, any update on yours?
Slow progress, but the good news is that sellers found houses (2 families living in the house hence the the 2 kitchens problem). One found a house with no chain, also good. The other says he's willing to move out sooner if his sale is not completed in time.
Another difficulty we had with finding lenders, not many considered us because the house was extended more than 40%, including Halifax. The house was doubled in size in 1992, just a bit over 50%. So many stupid rules...