Based ona random ad that appeared I don't know where, I went looking at airfare prices. And found that there are some really good fares available on American, Delta, Lufthansa for the spring. Out of several tempting choices we booked Philly to Edinburgh and back from Dublin, non-stops, for $455, mid-April. Saw similar for various combos into Germany, and Paris-London open jaws, among others.
For those interested, happy hunting!