1925 20 UPU to France, registered, shortpaid, postage due

1925 Hull Centre, Ontario (MR 10) ties 1c, 3c(3) Admiral on registered cover to Calais, France, shortpays the 20c UPU registered rate (10c+10c registration), rated “T100”, French dues tied on reverse (50c pair, 5c single fault), London, GB registered transit hs etc.