A 'softie', in case you don't know, is an accessory that screws into a standard cable release socket, on cameras that have them, to increase the height of the shutter release and create a wide button to press. They allow the finger to be wrapped over the top of the release so the release can be squeezed, like a trigger on a gun, rather than pressed with the tip of the finger. The idea is, just like a gun, by squeezing the release 'softly' you are less likely to cause movement of the camera.
While experimenting with the grips I fitted to the 139 I noticed I was causing a small movement of the camera each time I pressed the release. I've used softies before on other cameras and thought it might help. But, of course, there's no cable release socket on the 139 release. My answer? I cut a small round piece of foam and stuck it to the release button. I used some 3mm thick, closed cell, foam and cut it with a 10mm punch. It fits well and gives exactly the same effect as other softies. And, most importantly, it stopped the small movement that I was previously introducing when pressing the shutter release.