Hey there!
I recently did mine, its not easy i tell you.
I messed up 3 cases to find a good one, in the end i went for a full tower (its huuuge!) to avoid the need for a 90° PCMCIA adaptor for the NIC.
When i was doing mine, i didnt really focus on what the back looked like, tbh - i didnt care as that wasnt going to be seen anyway. So... I cut out a great big hole in the back, cut out little bits here and there inside, moved the power supply to a different place and then cut out and glued a section of the original a1200 case ( the bottom bit ) to one side of the tower.
Hey Presto! No need to mess about trying to mount the a1200 mobo on mounts that are not there, etc! It just sits niceley in the original a1200 case bottom, with no need to drill mount holes or worry about shorting the a1200 mobo on the bottom of the case.
I can take some photos if you like, but its not pretty, but it works.
Obviously from the front you cant tell at all, and the a1200 is very stable in its new home. Now where is that PPC.... :-)
