[John Sabato]

There should be no reason why you cant pull up the toggle after dropping the firing pin, and holding the trigger in the rear position... In my experience, there is no mechanical interference that could cause this in the pistol's engineering.

The only reason I can think of why you might not be able to raise the toggle in such an action is if the safety is placed in the "on" position before you let go of the trigger... try your test without the sideplate and see if it still won't let you raise the toggle. To drop the firing pin without the sideplate, just press inward on the forward portion. I also suggest you clean and lubricate all the moving parts and test again.