Shutter release power on
The F2’s advance lever has to be pulled out to switch on the finder. I found this cumbersome when I want to quickly check the exposure. Hence I’ve created a new modification which adds a momentary (push-on, release-off) power switch to the shutter release mechanism. Half press the shutter release button would switch on the finder, and further press would trigger the shutter.

Also the shutter release mechanism is modified so that the shutter button can be pressed down to switch on the meter, even when the shutter is not cocked.
DP-2AN turned on by pressing the shutter release button half way