Canberras and M117's makes sense. The 117 tails can be delivered from low level with fairly crude aiming equipment. The Vulcan used a bit of plastic with some fancy name that I can't remember but the dates fit as the 117's came in to service around the time of the '67 war when the Israelis demonstrated a need for a retard weapon. We had the 117 tail at that time but while not exactly secret it was not widely advertised.
The current US series of bombs are 8n s.