Thanks for the thoughts. Interesting: this site only mentions Liverpool (Bootle) but mine was sent to Old Hall St., Liverpool. Is that different. I know Liverpool is on strike too. I was always a bit confused about why the Bootle in brackets.
What frustrates me is that applications from abroad have no way of paying more for a faster service. I even tried repeatedly to book a Same Day appointment in London on a recent trip but could never find availability. I guess I can do nothing but wait and see… and Easter weekend means 4 days of nothing!