Is there something particular which appeals to the German psyche to visit places like the Scottish Highlands, Wales, Cornwal and Jersey ?
Dusseldorf seems to be the only urban non-UK European centre with purely seasonal leisure routes to these UK destinations
Helvetic also have a ZRH-INV, and there are quite a few Germany-Channel Island services on Summer weekends (and some from Rotterdam?)
And this Summer also saw some inbound charters from France to GLA, as a gateway to Scotland. EDI also has some seasonal services from continental Europe aimed at the inbound market (Niki, Orbest Orizonia from Madrid for example)