Update: None. I contacted the number for Royal Mail Inquiries today, and they do not even show the package as having entered the UK. So Germany says it's here somewhere, and here says it's not here anywhere.
Ho-hum......PayPal offers the helpful advice: "Since it is a trans-country shipment, why not wait a little longer?" And then what? I hope that whoever has it is making good use of it. I'm not!