Regular design, channel with end plates screwed on, but PCB won't slide out due to the springy strip causing too much friction between mosfets and case?
No idea about the mosfet pressure spring thing, sorry, haven't come across that before. I imagine poking around with pliers, tweezers, screwdrivers etc would get it.
Do you have a dentists mirror? They're useful for being able to see inside things. You can get really small ones with telescoping handles. They're great.
