There is a spreadsheet available for download from the cargo section of the UA web site which lists flights, and I believe code shares are not included. You can sort it by equipment, origin, destination, etc. It might list thru change of gauge flights though.

I live in BOS and basically UA flys to IAD, ORD, DEN, SFO, and LAX nonstop, and as far as I know it is all narrow body and express e.g. no 3 class equipment.

Also keep in mind that it may well be a valid routing to fly BOS>IAD>JFK>onward to the European destination. I know I use this routing for BOS-west coast flights in order to get P.S. but it does take some time.