Got it back Gummy - thanks so much! However still no joy I get a shakey movement on the mouse config screen of Impulse X whereas before it was dead. But not moving now as it should. This is selecting both Amiga and ST mice.
In the "Controller Configuration" screen of Impulse X you need to set two things:
1) The "Rotary Device" type, in your case set this to "Amiga mouse".
2) The "Adapter" type. Unfortunately MacRorie didn't post the pinout of his PCB, but judging from the photo it seems he is following the pinout that i published in the 1990ies. So the proper setting for this adpater should be "ST M. Adapter M.Domin".
A wrong combination of "Rotary Device" and "Adapter" will show the effect of "shaking" when you move the mosue, but the mouse buttons should usually work.
Hope this helps