Posted on Wednesday, February 24, 2010 - 03:48 am:
I think the back plate is part of the shutter body casting. Normally you would remove enough of the main components of the shutter and then lift out the mechanism base plate. Under that are the shutter blades and a plate that separates them from the aperture blades.
Posted on Wednesday, February 24, 2010 - 11:46 pm:
I think OP allready knows about the backplate. He removed the 3 shutter plate fastener screws there. Wonder if any more are hidden under the inside shutter components.