PC Engine & Core Lil' Help

Fellow Turbo Gamers,
Does anyone know if the insides of a PC Engine and Core Graphix 
are the same?  I don't have that funky screwdriver to open it and 
look for myself?  The Core seems to have a bigger hump on top.  
This leads me to a second question: Can you switch shells 
between the two consoles?
Keep Gamin',
Richard
xxxxxx@yahoo.com