The Loral ALQ-157 or Saunders ALQ-144 would be a good bet in the 80s. The former was mainly C-130, Chinook and SK4, the latter Army Lynx.
When the RN wanted IRJ as a role fit for their Lynx, they borrowed 144s from the Army, despite having their own 157s. Beyond that, I don't know why. Perhaps because Army 2nd Line workshops were in-theatre, whereas SK4 support was minimal.