The other WW2 generation UK silenced pistol was the "sleeve gun".. a .32 cylindrical single shot weapon related to the Welrod (both were produced by SOE) which was designed to be concealed up the sleeve of a jacket. The trigger mechanism was at the front of the weapon and it was designed to be pressed up against the victim. This used rubber wipers and was, like the WELROD, very quiet!
We call the technique of pressing the muzzle against the victim a "contact shot." It's a very quiet way to shoot without a suppressor. The support hand retains the slide of a Browning tipping lock type pistol and manually cycles it after a shot is fired.