magnetic bearing from aircraft to beacon is 247 + 70 = 317
true bearing aircraft to beacon is 317 -14 = 303
true bearing beacon to aircraft (still measured at the aircraft) is 303 -180 = 123
true bearing beacon to aircraft measured at the beacon is 123 +/- convergency
on a polar chart convergency is change of longitude, 17W - 9W = 8 degrees
a quick sketch shows it should be subtracted
true bearing to plot is 123 - 8 = 115 degrees.