Nice one, Pace!
my trouble is I can never remember numbers, and in fact did transmit 7700 over Aboyne once....ATC sensibly assumed that a PA18 was NOT being hijacked, and phoned Deeside to sort things out later.
Later on, in Texas, talking to Houston enroute, having departed from a small airfield and filed a flight plan by phone, had a few minutes of radio not working, while IMC. Gave a real significance to all that training ...to FLY THE PLAN! which I did while pushing this and that and traced it down to the headset not being properly plugged in.
Houston hadn't noticed ....